What causes bloodshot eyes?

What does the term bloodshot mean? It basically means the blood vessels under the eye’s surface become larger and inflamed, causing the eye to look red. Some red eyes alone are usually benign and have no reason for concern. But if the redness is accompanied with pain or loss of vision, this may indicate a serious medical problem and may need immediate medical intervention.

Listed below are some of the causes for eye redness:

Allergies

One of the most common causes of redness is allergens in the surroundings. Outdoor allergens such as pollen from plants and trees. Indoor allergens consist of dust, pet fur, pet dander and even mold. The redness is often paired with itchiness, sneezing and teary eyes. This is referred to as allergic conjunctivitis, which isn’t contagious.

Dry eye

When the lacrimal glands do not produce enough tears to lubricate the eye, this can result in dry eyes. Sometimes some hormonal medications (HRT) such as estrogen can cause dry eyes as a side effect.

Subconjunctival Haemorrhage

Our conjunctiva contains many capillaries and blood vessels. If these vessels break, blood can leak into the white and the conjunctiva, which then builds up in a clump to cause subconjunctival haemorrhage. Sometimes, the simple action of coughing or sneezing can cause this to happen. People who have medical conditions such as diabetes, high blood pressure and are on blood thinners are more prone to this occurring. These bleeds may look serious, but they are usually painless and do not affect vision. It will resolve within 7-10 days.

Conjunctivitis (Pink Eye)

Close-up_of_an_eye_with_redness_and_visible_blood_vessels,_indicating_possible_eye_irritation,_infection,_or_conjunctivitis.

Conjunctivitis is the infection of the thin transparent membrane of the eye called conjunctiva. The most common ones are viral and bacterial conjunctivitis. Both are equally contagious and can spread easily. These are sometimes accompanied by a sticky discharge, watery eyes, a gritty burning sensation, sensitive to bright light or crusting of the eyelids in the morning.

Blepharitis

This is when your eyelids are inflamed, which causes your eyelids/eyes to be swollen and red. The symptoms may be similar to those of conjunctivitis, so it is advisable to get it examined by a doctor to determine what is the cause of your red eye.

Alcohol

Excessive drinking of alcohol can lead to bloodshot eyes. The alcohol content causes vasodilation of blood vessels, so more blood gets filled into these dilated vessels, thus making the eye look red. Alcohol is also a type of diuretic which makes the body (and the eye) dehydrated after frequently urinating. When the eye is dehydrated, it’ll then lead to dry eyes.

Contact Lens Wear / Corneal Ulcers

People who wear contact lenses touch their eyes more often than those who do not. Thus, they are more prone to getting eye redness, if not, eye infections. Sometimes, removing contact lenses can result in scraping or scratching the cornea. Overwearing of CLs over the given timeframe may lead to neovascularization (redness). Sleeping with CLs, or unhygienic practice of cleaning CLs may lead to corneal ulcers. Action must be taken immediately if corneal ulcers arise.

Acute angle closure glaucoma

There are different types of glaucoma, but one to take note of in regards to eye redness is acute angle closure glaucoma. The redness is usually accompanied by an intense pain in the eye, haloes/rainbow rings around light, blurred decreased vision, headaches and nausea/vomiting. The iris of the eye prevents eye fluid from being drained out properly, and as the fluid builds up, this will increase eye pressure rapidly. This is usually an emergency case and has to be seen by a doctor immediately to help to bring the eye pressure down to prevent vision loss.

Episcleritis/Scleritis

Episcleritis is the inflammation of the layer between the conjunctivitis and sclera. Symptoms consist of mild pain, redness and tenderness when touched. This is easily treated with artificial tears, and if needed, steroids to keep the symptoms at bay. It will usually resolve within 10 days.
On the other hand, Scleritis is the inflammation of the sclera which causes the eye to be very red. This is usually caused by an autoimmune condition, so it will need immediate medical attention. Patients will be given anti-inflammatory medication and topical steroid drops.

Uveitis

This is the inflammation of the middle layer of the eye called the uvea. Symptoms come in the form of pain, redness, blurred vision, and sensitivity to light. This must be treated immediately with steroids to bring the inflammation down. If not treated, it may cause retinal/choroidal scarring or even uveitic glaucoma.

Injury – trauma to the eye

Simple actions like accidentally poking your eye with your mascara applicator, or kids playing roughly and fingers poking each other’s eyes, can result in injuries to the eye. When the eye is injured, blood vessels in the eye will dilate to bring more blood cells to the site of injury to repair and heal the injury.

Swimming

Spending a certain amount of time in the pool can cause bloodshot eyes as there is chlorine in the pool which then irritates the eyes.

Lack of sleep

Not getting enough sleep can also lead to red eyes. Not enough rest means no proper blood/fluid circulation, so this makes your eyes look puffy and red.

Smoking

Cigarettes contain harmful toxic chemicals which are irritable for the eyes. When the eyes get in contact with these chemicals they will react and cause their eyes to be red.

All in all, as long as you have a red eye (which sometimes may be accompanied with pain, discharge or blurred vision), it is advisable to seek medical attention to determine the cause and treat it when necessary, to prevent other issues from arising.

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Swimming with Contact Lenses

Swimming with contact lenses on may seem like a great idea because without them, you cannot truly see clearly while you’re out splashing away in the waters. However, by doing so you risk numerous eye issues which could be dangerous and may not be worth it after a fun day at a pool or beach. Here are insights regarding the risks of swimming with contact lenses on and precautions you can take to protect your eyes better in the water.

What are the Risks Swimming with Contact Lenses on?

The FDA does not advise for contact lenses to be exposed to any kind of water. This is due to the nature of soft contact lenses to absorb water, trapping potential bacteria, viruses, or other pathogens on the eye which makes the wearer susceptible to certain eye issues when worn to swim at the pool or beach. On another note, swimming in a pool may be less eye threatening than swimming in lakes, rivers and out at sea. The reason may appear obvious as water in lakes, rivers and the sea contain a variety of bacteria, viruses, and other harmful pathogens that often would be mostly eliminated by pool chemicals. However, that does not mean wearing contact lenses to swim at the pool is safe. In fact, chlorine and other pool chemicals are not able to completely eliminate pathogens. Rigid gas permeable (RGP) contact lenses should never be worn to swim, as they are easier to dislodge from your eye. Soft contact lenses on the other hand are more likely to remain on your eye when swimming, but they are porous and can absorb chemicals and bacteria, increasing the risk of eye irritation and infection. Wearing your contact lenses while swimming could increase your risk of the following issues:
  • eye irritation due to lens adherence on the eye
  • dry eyes, especially after swimming in chlorinated or salt water
  • eye infections
  • corneal abrasion (scratched cornea)
  • eye inflammation (uveitis)
  • corneal ulcers

What about Showering with Contact Lenses On?

The risk of this is similar to swimming with contact lenses on. According to the Centre for Disease Control and Prevention (CDC), there’s a type of microorganism called Acanthamoeba which is found in all types of water. It is more commonly found in tap water and well water, which are the ones you shower with. This amoeba may cause a serious eye infection called Acanthamoeba Keratitis which presents as eye pain and can be very difficult to treat. In rare cases, it may even lead to blindness. Tips for Swimming Safely
  1. Goggles Swimming goggles work well enough to reduce the risk of eye infection if you are going to wear contact lenses anyway. Not only does it protect your eyes from contaminants, swim goggles also helps to prevent your lenses from coming off.However, it is still highly recommended to take your contact lenses out before coming into contact with water. In the case where your vision is poor without corrective lenses, you could consider investing in a pair of prescription swimming goggles. These could too come with UV protection which would be an added benefit against sun damage to the eyes.
  2. Refractive Surgery and Other Alternatives Many of those, typically with an active lifestyle and sporty, choose to undergo refractive surgery to correct their myopia (shortsightedness), hyperopia (longsightedness), or astigmatism with laser eye surgery. With this, you can say goodbye to glasses and contact lenses.There are various types of laser refractive surgery such as; TransPRK, LASEK, LASIK and various other technologies. Each to their own reshapes the cornea using a computer-controlled laser beam. Refractive surgery allows light to enter the eye and properly focus on the retina for clear vision. These surgeries have a good safety profile with most people achieving 6/6 vision without glasses or contacts after the laser procedure. Nevertheless, all surgeries come with possible risks and complications, which needs careful consideration before undergoing the procedure. Another alternative is Ortho-K, or orthokeratology. It is a non-surgical method to temporarily correct your refractive error and reduce the need to rely on glasses or contact lenses. Generally it is a type of hard contact lenses that are specifically designed and fitted to reshape the cornea. Typically worn at night while you are asleep, it allows you see clearly when you remove the lens in the morning when you’re awake. It is a safer non-permanent alternative for those who are concerned about permanent refractive surgery.
Your eye doctor or eye care practitioner would be able to better advise you on alternatives to swimming with eye correction to accommodate your lifestyle.

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Hydroxychloroquine Drug Toxicity to Eye

Hydroxychloroquine is a controlled medication for several dermatologic and rheumatologic conditions. It is also widely used to treat Systemic Lupus Erythematosus (SLE) disease and Malaria (by using Chloroquine originally). The maximum recommended dose is 5 mg/kg/day which is commonly used in SLE patients. Recent research trials suggested that high dose HCQ is a possible potential use for coronavirus, COVID-19 therapy by reducing viral replication, but there is insufficient evidence supporting its efficacy. Ongoing long term usage and high dose of hydroxychloroquine can cause unwanted side effects to the body including eyes.

Side effects

  • Dizziness
  • Headache
  • Ocular toxicity
  • Skin rash
  • Gastrointestinal upset such as diarrhoea, vomiting and stomach cramps

In severe cases seizures, angioedema, arrhythmia, and bronchospasm may occur. Long term hydroxychloroquine usage can cause toxicity to the eyes as well including the cornea, ciliary body and retina.

Eye diseases

Chloroquine was initially used to help treat malaria. Chloroquine is less often used now because its derivative hydroxychloroquine is better. Hydroxychloroquine is commonly used to treat inflammation in diseases like rheumatoid arthritis and dermatitis. The toxic effects of this substance on the retina are seen in the area known as the macula. Some people may have early signs of toxicity, such as changes in their vision. More advanced toxicity may involve complaints like difficulty seeing in colour or a scotoma (a dark spot on the centre of your vision). Advanced hydroxychloroquine toxicity can cause a bull’s eye maculopathy. Since retinal toxicity is usually irreversible, finding out if someone has retinal toxicity and stopping the thing that is causing the toxicity as soon as possible is the best treatment. Corneal toxicity is when a drug gets deposited into the cornea. This is very rare, and it typically doesn’t affect vision. In rare cases, ciliary body dysfunction can happen and influence the eye from focusing.

Risk factors

Hydroxychloroquine retinopathy is more common in patients with longer duration and daily dosage of the drug. Patients are at higher risk of retinopathy if they use hydroxychloroquine for more than 5 years as treatment.

Fundus_images_showing_hydroxychloroquine_retinopathy_with_bull's_eye_maculopathy,_highlighting_retinal_pigment_changes_and_central_vision_loss.Signs

Hydroxychloroquine retinopathy is usually bilateral and symmetric. The early signs include macular edema and granular depigmentation in the retinal pigment epithelium in the retina. It can progress to an atrophic bull’s eye maculopathy if continuous drug exposure causes widespread other areas of the retina including optic nerve. Hydroxychloroquine keratopathy is seen as an intraepithelial deposit. Ciliary body dysfunction can be detected when the near vision is poor.

Symptoms

Initially, hydroxychloroquine toxicity may cause few or no symptoms. However, over time, symptoms may develop such as hard to differentiate colour, loss of central vision, reading difficulty, blur of vision, glare, flashing of lights, and metamorphopsia. It usually affects both eyes. In keratopathy, patients may experience halos around light and photophobia whereas in ciliary body dysfunction, will complain of reading difficulty and find it hard to focus on near work.

Treatment

Early detection of hydroxychloroquine toxicity can be stopped to prevent further retinal damage and visual loss. Patients who start hydroxychloroquine as medical condition treatment should be on regular eye examination, especially those who are on exposure drugs for more than 5 years. There is no treatment that can be done by surgery at the moment. Hydroxychloroquine retinopathy is not reversible as the damage appears to continue for a period of time. However, the early detection of retinopathy can prevent further visual deterioration. It can be treated in keratopathy cases. If you are a patient with ongoing hydroxychloroquine, it is advisable to have an eye examination with an ophthalmologist to rule out any eye disease.

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What is Low Vision?

Low vision is a condition where decrease in visual acuity or visual field constricted to the point where glasses, contact lens, medical or surgical treatments cannot be fully corrected. Low vision is a vision problem which will interfere with an individual’s daily activities such as driving, reading, etc. The National Eye Survey 1996 estimated that there were 540,000 people with low vision and about 50,000 people who were blind in Malaysia. Prevalence of low vision was found to be 2.44% and those who were blind were 0.3%.

What causes Low Vision?

It is often caused by eye diseases or conditions such as: cataract, age-related macular degeneration, diabetic retinopathy, glaucoma, retinitis pigmentosa, albinism, retinopathy of prematurity, amblyopia, strabismus, uncorrected high refractive error and eye injuries.

Symptoms & Types of Low Vision

  • Loss of central vision
  • Loss of peripheral vision
  • Blurred vision or hazy vision
  • Night blindness
  • Decrease in contrast sensitivity
  • Difficulty differentiating colors
  • Difficulty recognizing objects at a distance and near

Treatment

Unfortunately, low vision is usually permanent. An individual who was diagnosed with low vision can undergo low vision therapy. Low vision therapy will be done by an optometrist or an occupational therapist who specializes in low vision. The purpose of low vision therapy is to help individuals continue performing their daily activities. This is achieved by providing appropriate optical devices and special training in the use of residual vision and low vision aids, which range from simple optical magnifiers to high magnification video magnifiers. Low vision devices can be optical (telescope, magnifying glasses, magnifiers, etc.), non-optical (extra illumination, typo scope, books with enlarged text, writing guides, clock with large numbers, keyboard with large letters, etc.) and electronic device (Closed-circuit television (CCTV) or portable electronic devices). There are some resources centers that can help low vision patient such as:

  • Social Welfare Department (JKM)
  • Ministry of Women
  • Family and Community Development, Malaysia
  • Special Education Division, Ministry of Education, Malaysia
  • Malaysian Association for the Blind (MAB)
  • Society for the Blind Malaysia (SBM)
  • St. Nicholas Homes Center
  • Sabah Society for the Blind (SSB)
  • Sarawak Society for the Blind (SKSB)

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What is Perfect Vision: 6/6 or 20/20?

People claim to have perfect eyesight if they have 20/20 vision or 6/6 vision. What does it actually mean?

The sole difference is the unit of measurement in feet and metres, respectively. When at 6 metres, and being able to see what a regular individual can see at 6 metres, the person would have 6/6 vision. Whereas, 20/20 vision depicts the same function, albeit at 20 feet instead of 6 metres. In Asia, these measurements are used interchangeably.

The visual system functions in the way that it processes visual information for us to be able to see features and images at far distances. We inherit the integrity that builds our visual system from our parents and the way it develops during early childhood. Within a populace of individuals with healthy eyes, the prime vision achieved would

vary from slightly better than most (6/4 or 6/5) to slightly poor (6.7.5). An example of these in our daily lives are; an individual is legally allowed to drive in Malaysia if they could attain a vision measurement of 6/12 in their better seeing eye with corrective spectacles.

Snellen_eye_chart_displaying_letters_in_decreasing_sizes_used_for_vision_testing,_with_measurements_in_feet_and_meters_to_assess_visual_acuity,_including_20/20_and_6/6_vision.

What assessments can test for 6/6 or 20/20 vision?

The examiner will start the vision testing by asking you to read letters from the chart (commonly known as a Snellen chart). The test will be tested one eye at a time, and then with both eyes. The examiner can then measure your vision.

These results will provide important information regarding your vision and the prescription necessary to correct it.

Why is having good vision so important?

  • Safety: By having a poor vision, activities such driving, biking, cycling and even walking can be dangerous for you and others. In Malaysia, the minimum vision requirement is 6/12 (20/40) vision or better to be considered safe to drive on a public road.
  • Comfort: A clear vision allows you to have more freedom in your daily activities. Having good vision means that you won’t have to squint, whether you’re sitting at the back of the classroom or at the back row of the film theatre. You don’t have to strain your eyes to see things if you have good vision.
  • Reading ease: Having good vision enables you to read comfortably and learn better.
  • Quality of life: A good vision will provide you a better quality of life.

What causes you to have poorer than 6/6 or 20/20 vision?

Basically, there are various possibilities that can cause vision to be worse than the optimum 6/6 or 20/20 vision. The most common one are refractive errors such as:

  • Far-sightedness (hyperopia)
  • Near-sightedness (myopia)
  • Presbyopia: A condition that makes it more difficult to focus on a close up object as you get older, due to aging
  • Astigmatism: A condition caused by irregularity of the front part of the eye (cornea)

However, there are also many different eye disorders or diseases that can affect your eyesight, especially for those who are having systemic disease such as diabetes and hypertension.

How can your vision be improved if it is not 6/6 or 20/20?

There are several ways to help eyes to see clearly after you get your vision tested by an eye practitioner. The eye care professional with advice on the treatment options that fit and work the best for you, which may include:

  • Glasses: Glasses or spectacles are the most conventional way of vision correction. It is very practical, affordable and safe. They work by refracting the light to focus on the retina, which helps you to see clearly.
  • Contact lenses: Contact lenses work the same way as glasses to provide you a clear vision. However, it is more convenient and suitable for physical activities, especially for those who have an active lifestyle. Some people also prefer contact lenses for cosmetic purposes. Also, in certain refractive error conditions, contact lens correction can give better vision. Example, for those who have a large difference in refractive error or “power” between both eyes.
  • Refractive surgery: Refractive surgery is performed by changing the refractive, or light-bending, properties of the eye. It is functional because it allows you to see clearly without depending on glasses or contact lenses. However, some may not be good candidates for refractive surgery due to various reasons. Examples of refractive surgery include Implantable Collamer Lens (ICL), laser treatment such as TransPRK, and cataract surgery.

What will happen to your vision as you get older?

As you get older, your vision may be affected, despite having 6/6 or 20/20 vision at distance throughout your younger years. Those in their 40s will begin to have some difficulty focusing on close objects or small print, and some might have difficulty telling colours apart. Two common eye conditions caused by aging are presbyopia or cataract

When should you visit an eye practitioner or eye doctor?

You should visit an eye practitioner or eye doctor when you have a condition such as:

  • Eye pain
  • Blurry vision
  • Headaches due to eye strain
  • Eye redness
  • Eye swelling

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Nutrients & Vitamins for Eye Health

Nutrition play an important role in slowing the progression and preventing the onset of ocular diseases such as Age-related Macular Degeneration (AMD), glaucoma, cataract and so on. Studies show getting sufficient essential nutrients can preserve good vision and eye health. Antioxidant-rich foods and supplements such as anthocyanins, carotenoids, flavonoids, and vitamins have been shown to lower the risk of getting eye-related diseases such as Age-related Macular Degeneration (ARMD).

  • Vitamin A
    • A study showed the reduction of glaucoma risk among a population of black women with intake of fruits and leafy green vegetables high in vitamin A. The sources of vitamin A include dark green produce such as kale, mustard, collard, and broccoli, orange produce such as carrots, sweet potatoes, papaya, egg yolks and whole milk.
  • Vitamin C
    • Vitamin C functions as an antioxidant and it can lower the risk of developing early cataract and helps to slow down the progression of age-related macular degeneration (AMD) and vision loss. The sources of vitamin C are citrus fruits, red and orange produce such as tomatoes, cantaloupes, peppers, green produce such as broccoli, cabbage. Other than that, cauliflower and berries are also rich in vitamin C.
  • Vitamin E
    • Vitamin E works well together with vitamin C to protect against the unstable molecules (free radicals) that damage the healthy tissue on your eyes. The sources of vitamin E can be found in egg yolks, avocados, butter shrimp and dark green leafy vegetables.
  • Lutein and Zeaxanthin
    • Many studies show that lutein and zeaxanthin lower the risk of age-related macular degeneration (AMD) and cataract. The sources of lutein and zeaxanthin can be found in dark green leafy vegetables and fruits such as broccoli, peas and corn.
  • Zinc
    • The human eye contains high levels of zinc which plays an important role in eye health. Zinc helps to transport vitamin A from liver to the retina to produce melanin where melanin acts as a protective pigment in the eye. The sources can be seafood, nuts, seeds, cheese, yoghurt, soybeans and so on.
  • Essential fatty acids
    • Essential fatty acids aid visual development and retinal function. It functions by fuelling cells and optimising central nervous system function. Omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic (DHA), are vital in vision development and maintaining proper eye and retinal function. Sources of omega-3 fatty acids include cold water fish such as salmon and sardines.

Assorted_fruits_with_wooden_blocks_spelling_"vitamins.

A sufficient amount of nutrients & vitamins play an important role for a healthy eye. However, excessive intake of vitamins or supplements may sometimes reverse the effect causing unnecessary problems as well. For example, high doses of beta carotene (Vitamin A) intake can lead to lung cancer. Therefore, it is encouraged for people who are having vision problems and with poor control of diet to seek advice from eye professionals for the right food to maintain their eye health. An eye health professional can help you create a diet plan which is suitable for you and helps to reduce the chances of developing age-related eye diseases.

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Is Headache Related to the Eyes?

One of the most common symptoms that many people face is a headache. Even if you think you can treat a headache on your own without seeking medical attention, you should be concerned if the headache is accompanied by symptoms like blurred vision, slurred speech, weakness, numbness, or seizures. Genes can play a role in headaches, especially migraines.

Headaches can also affect the eyes and vice versa. That much is true. When you have a headache, the area around your eyes can occasionally hurt. Here are a few types of headache that are linked to the eyes.

  1. Eye strain headaches are triggered by poor posture, lack of sleep, being hungry or dehydrated or when your eye muscles contract too much when working for prolonged periods at near work. It will cause pain and discomfort behind your eyes, on one or both sides of your head, and from your neck down to your shoulders.
  2. Ocular migraines cause visual disturbances with or without headache. The cause is unknown, but genetics can be a contributing factor. People with ocular migraine may experience symptoms like seeing flashing lights, blind spots in the field of vision, severe eye pain, and headaches.
  3. Uncorrected refractive errors such as short-sightedness (myopia), long-sightedness (hyperopia), astigmatism, and presbyopia also interfere with proper vision and may cause squinting to help the eyes focus. If left untreated, it may also cause headaches.
  4. A sinus headache can develop due to a sinus infection. Many people don’t realise that having sinusitis means not only feeling pressure around the nose area. Actually, the sinus pressure also occurs around the eyes, cheeks, and mouth, which gives the same feeling as a headache.
  5. Headaches due to glaucoma most commonly occur around the eye or forehead. Glaucoma is divided into two types, which are primary open angle glaucoma (POAG) and acute angle closure glaucoma (AACG). One of the symptoms of AACG is headache.
  6. Ocular Ischemic syndrome develops due to a chronic lack of blood flow to the eye. People having this problem might have symptoms like headaches and a decrease in vision.

Home remedies for relieving headache symptoms:

  • Taking over-the-counter painkillers is able to relieve mild to moderate headaches. If you have a severe headache, do see a doctor immediately
  • Resting in a dark room
  • Apply cold compress to the back of the neck, the forehead or the eyes
  • Follow the 20:20:20 rule to relieve eye strain due to long-term near-work
  • Sitting with good posture
  • Drink more plain water

A_man_experiencing_a_headache_with_red_highlighted_areas_on_his_forehead_and_temples,_indicating_pain_or_tension,_possibly_related_to_eye_strain_or_migraines.

Despite the fact that headaches are relatively common, they should not be taken lightly as daily activities can be interrupted. To rule out any eye disorders, do see an ophthalmologist. The sooner you receive a diagnosis, the sooner you can start receiving treatment to relieve your symptoms.

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Colour Vision Deficiency

Colour vision is important in our daily life in order to let us perceive better images about our living environment. Colour vision is the ability to discriminate between different colours. Our colour vision perception is also known as photopic vision, which is appreciated by cones cells. The cones cell is mainly located at the centre part of the retina, which is the fovea area. There are 3 primary colours sensed by the cones cell in fovea which are blue, red and green. Sensation of other colours such as white, yellow, orange, purple can be produced by mixing the 3 primary colours in different combinations.

Primary_colors_Venn_diagram_showing_red,_green,_and_blue_color_mixing.

3 Primary colours

Various tests that can be used to diagnose colour vision deficiency in our clinical field. The Ishihara chart is the most common and simple test that we always use to diagnose colour vision deficiency, especially red-green colour vision deficiency. Moreover, the Farnsworth D-15 hue test can also be used to diagnose colour vision deficiency. The Farnsworth Munsell 100 hue test was a more advanced test that we can know in more detail what exactly colour vision deficiency that the patient had. These are the common tools that we used to diagnose colour vision deficiency in the clinic.

Ishihara_color_test_book_for_detecting_red-green_color_blindness.

Ishihara plate

Farnsworth_D-15_hue_test_kit_for_assessing_color_vision_deficiency.

Farnsworth D-15 hue test

Farnsworth_Munsell_100_hue_test_for_detailed_color_vision_analysis.

Farnsworth 100 hue test

 

Basically, colour vision deficiency can be divided into 3 categories which are deutan, protan and tritan. Deutan patients mainly will have weakness in perceiving green colour or completely cannot perceive green colour, whereas protan is the patient having difficulty in perceiving red colour or completely cannot perceive red colour. Moreover, tritan mainly will cause patient difficulty in perceiving blue colour. Colour vision deficiency can be categorised as inherited or acquired. Acquired colour vision deficiency is usually caused by drug use or some ocular disease.

Comparison_of_normal_vision_vs_red,_green,_and_blue_color_blindness.

For your info, red-green colour vision deficiency is more common as compared to blue-yellow vision colour deficiency. However, male had higher risk compared to females to have colour vision deficiency as it is an X-linked disease. As male only have 1 X chromosome so if their mother passed the gene which is lack of colour vision, the son is likely to have colour vision deficiency. Females who have a father with colour vision deficiency has a 50% chance to transmit the disorder to their sons. The prevalence of colour vision deficiency worldwide is reported to be 8% in male and 0.5% in females. With early detection proper counselling can be done to the patient in order to adapt and have an idea on what is the suitable future pathway or profession that can be pursued. Hence, it is important for us to screen for colour vision deficiency especially in young male children as they have higher prevalence in getting inherited colour vision deficiency.

There are no available treatments for colour deficiency at the moment. However, there are special tinted lenses or contact lenses that can help the patient to have better perception of the colour. Early detection of colour vision deficiency since young children is vital in order to overcome the limitations such as future career pathways. We don’t treat colour vision deficiency people as disabled as they only have difficulty in differentiating colour, but the vision was usually normal. We can always provide guidance and advice for colour vision deficiency patients in choosing the right pathway or profession in the future. For acquired colour vision deficiency, we can treat the underlying problem in order to resolve the colour vision deficiency problem. Therefore, it encourages parents to bring their children to visit an eye specialist/ophthalmologist for a proper consultation which includes colour vision screening, especially for male children.

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Eye Twitching

Why is my eye twitching?

An eye twitch is an eye muscle or eyelid spasm that causes an involuntary or abnormal blinking of your eyelid. The lid moves every few seconds and lasts for a minute to two. In severe cases, the vision can be affected. Eye twitching can occur in both upper and lower lids.

Types

Generally, the three different types of eye twitching are eyelid myokymia, essential blepharospasm, and hemifacial spasm.

  1. Eyelid myokymia – This condition is usually benign where a mild spasm occurs in the lower or upper lid in either one or both eyes. Ocular myokymia can arise from stress, excessive caffeine, or tiredness.
  2. Essential blepharospasm – This is a bilateral, benign, and rare condition which typically causes frequent blinking and irritation in both eyes. Generally, it happens in middle to late adulthood and is more common in women than in men. The condition can gradually worsen over time, leading to symptoms such as light sensitivity, blurred vision, and partial or complete eyelid closure, and in certain cases, facial muscles can be involved.
  3. Hemifacial spasm – This condition will only affect one side of the facial muscle, causing spontaneous twitching of the eye along with the mouth, cheek, and neck. This is because a small artery is pressing on the facial nerve. It is more common in women than men, and especially in Asians. In severe cases, it may cause an inability to open the affected eye.

Causes

Eyelid twitching or spasms may be caused by:

  • Eye irritation or strain
  • Environmental irritants (wind or air pollution)
  • Fatigue or lack of sleep
  • Physical exertion or stress
  • Intake of alcohol, tobacco, or caffeine.
  • Medication side effects

Other ocular conditions that can cause twitching sometimes include:

In rare conditions, eye twitching can be symptomatic for people with brain or nerve disorders such as:

  • Bell’s palsy (facial palsy)
  • Dystonia Cervical dystonia (spasmodic torticollis)
  • Oromandibular dystonia
  • Multiple sclerosis (MS)
  • Parkinson’s disease
  • Tourette syndrome

Tips_to_stop_eye_twitching

Treatment

  1. Eyelid Myokymia
    Generally no treatment is required as this condition will resolve spontaneously. However, a healthy lifestyle might help to prevent it by avoiding stress, getting plenty of rest, and reducing alcohol, tobacco, and caffeine intake. Sometimes, correcting refractive errors and applying lubricant to dry eyes can improve the condition.
  2. Essential blepharospasm 

    Botulinum toxin injections are the most common treatment for blepharospasm. However, it can also be treated with medications, biofeedback, and surgery. This condition may require long-term treatment as it can cause significant functional impairment.
  3. Hemifacial Spasm
    A neurosurgical procedure known as microvascular decompression can generally successfully relieve facial spasms, although there are possible complications. Besides, botulinum toxin injections also help relieve eyelid and facial spasms. However, post-injection side effects are possible, such as minor bruising, temporary eyelid drooping, or temporary double vision.

Most minor cases of eyelid twitching will go away without treatment in a few days. However, if twitches are progressive and persistent for weeks to months, medical attention from an ophthalmologist is required without delay.

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Astigmatism

Astigmatism (散光 in Mandarin / ‘silau’ in Malay) is a common type of refractive error that can cause blurred or distorted vision. Other types of refractive errors are myopia (short-sightedness), hyperopia (long-sightedness) and presbyopia. Astigmatism is usually caused by an imperfection in the curvature of the cornea, causing a person to see images that are blur or not in focus at all distances.

Comparison_of_normal_vision_and_astigmatism_with_cornea_shape_differences_and_focal_points.

If your cornea is almost perfectly round in shape, it is able to focus light onto a single point. However if both your cornea and lens is more oval than round, instead of focusing onto a single point, it focuses on multiple points on the retina (back of the eye). When the cornea or lens shape is highly irregular, a person may experience significant blur vision at all distances.

Who is at risk for astigmatism?

Astigmatism can affect both children and adults. It may be congenital, or present at birth due to the natural shape of the eye. In babies, astigmatism usually resolves by the first year of life. However, there are some children who do not outgrow astigmatism and this can negatively impact their learning and development. Thus, it is necessary to schedule for periodic eye examinations for children to detect astigmatism or other refractive errors. Parents who have been diagnosed with high astigmatism should get their child’s eye tested for severe astigmatism as it is believed to be hereditary. Some people can also develop astigmatism after an eye injury or surgery. Those with a family history of keratoconus (degeneration of cornea) should also get their eye tested for high astigmatism at an early age.

Normal_eye_vs_keratoconus_showing_corneal_bulging_in_keratoconus.

What are the symptoms of astigmatism?

The most common symptom of astigmatism is blurred and distorted vision at all distances. Many people with low astigmatism may not have any symptoms. Those with astigmatism of 0.75D and above will start to have noticeable symptoms. These signs and symptoms include headache, eye strain and squinting to see clearly. Astigmatism can also cause shadowing of images which makes letters appear double. Night vision can also be poor due to debilitating glare and halos around lights.

Night_driving_vision_with_astigmatism_vs_without,_showing_blurred_vs_clear_lights.

What are the treatment options for astigmatism?

If the astigmatism is mild, your eye care practitioner may suggest no treatment at all. If you have moderate to high astigmatism, corrective lenses either glasses or contact lenses are the most suitable treatment options. Eye glasses contain special cylindrical lens prescription to correct astigmatism. Both soft toric contact lenses and rigid contact lenses can correct astigmatism. For high astigmatism (above 3.00D), rigid gas permeable lenses may be a better option. Surgical treatments of astigmatism include refractive surgery by reshaping the cornea via TransPRK or implantation of ICL. If you have cataract in your eyes, a toric IOL can be implanted in your eye to simultaneously remove the cataract and correct astigmatism.

How is astigmatism diagnosed?

A comprehensive eye examination by an optometrist or ophthalmologist will help to diagnose astigmatism. Children who have astigmatism rarely report it to their parents. Therefore, parents should look out for signs and symptoms in their children such as eye rubbing, squinting to see things, moving closer to see things and closing of one eye. Regular eye examinations are important to maintain a high quality of life and productivity.

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