An intraocular lens (IOL) is a lens that is implanted into our eye(s) as a part of treatment for cataract. It is implanted during cataract surgery, after the natural cloudy lens has been removed. The lens in our eye is exactly like the lens of a camera.
The lens functions to focus light onto the retina. As we age, this lens becomes rigid and cloudy, such that it starts impairing our vision. If this happens to you, you may be advised to have cataract surgery to remove the cloudy lens.
The cloudy lens is replaced with an intraocular lens (IOL).
There are various types of lens implants that are used during cataract surgery. It can be classified into monofocal, multifocal or toric lenses.
The most common type of IOL used is the monofocal IOL. Monofocal IOLs are used to restore vision for one area of focus, usually to see distant objects clearly. For individuals who have presbyopia or astigmatism prior to cataract surgery, glasses will still be required to correct vision following surgery, usually for reading.
Toric IOLs correct astigmatism. Astigmatism is a refractive error that is caused by an uneven corneal surface. This causes blurry vision at all distances. So Toric IOLs can correct astigmatism as it has different refractive powers at different meridians. Patients would still require reading glasses for near.
Multifocal IOLs aim to give clear vision at all distances. There are three zones of focus for near, intermediate and far distances. This feature enables optimum vision and clarity at all distances. Multifocal IOLs are more suitable for individuals with healthy eyes. With this type of IOL, you will be able to see your mobile phone, read the newspaper and drive without using any glasses or contact lenses.
