What is a Cataract?
A cataract is one of the most common eye conditions and causes blurry vision due to clouding of the natural lens in the eye.
The human lens is located behind the iris (the coloured portion of the eye), and it is mostly made up of water and proteins. These specific proteins provide the lens its transparent structure.
When a cataract occurs, the lens becomes cloudy and is seen as a white cloudy ball in the centre of the iris.
- The development of a cataract can occur with the natural aging process of an individual.
- Cataracts can also be inherited or can develop in infants as a result of infections in the mother during pregnancy.
- They can form as a complication of other diseases such as glaucoma and diabetes, or can develop after certain injuries.
- Prolonged use of corticosteroid inhalers and eye drops, and excessive exposure to UV rays, X-rays and other radiation during radiotherapy, can increase the risk of cataract formation.
Any structural change in the lens proteins can alter its clarity and negatively impact vision.
The lens becomes more and more cloudy with time when a cataract occurs, and may be viewable as white patches in the centre of the pupil.
Symptoms commonly associated with cataracts include:
- Blurry or cloudy vision
- Faded colours
- Increased glare from lights
- Poor vision at night
- Multiple images
- Frequent change in eye prescription
Initially, only a small part of the eye lens is affected, and you will not notice any vision loss. The cataract later grows larger and your vision gets increasingly cloudy. At an advanced stage you may experience double vision or light flashes.
Cataracts may be classified based on their location within the eye, which include:
Cloudiness is present in the centre of the lens.
Cloudiness is seen as white spokes in the outer periphery of the lens.
Posterior Subcapsular Cataract:
This occurs at the back of the lens capsule, which is like a shell of the lens. It may develop quicker than the other types of cataracts and it is more commonly seen in patients with diabetes or on long term steroid treatment.
Cataracts do not heal on their own or with conservative treatment. Vision loss will only get worse and will lead to blindness if not treated by surgery.
To assess the impact of the cataract on your vision, your ophthalmologist will test your visual acuity. This test involves reading an eye chart from a certain distance with one eye at a time. A comprehensive eye examination will then be performed to assess the severity of the cataract. A slit lamp examination uses a microscope to examine the structures in front of the eye such as the lens and cornea which are illuminated by a bright line of light. A retinal examination may be performed to look for problems with the retina, the light-sensitive layer at the back of your eyes.