1. Age Related Cataract

• Nuclear Sclerosis:
In nuclear sclerosis the lens becomes hard and yellow as it ages, but this development is usually slow. There is greater impairment of distance vision than of near vision and, in the early stages, the hardening of the lens also causes the refractive power to change and  the lens to become myopic (nearsighted). In some cases patients are now able to read without their spectacles, a state called ‘second sight’.

• Cortical:
This is a peripheral cataract with the cloudiness located near the outer edges of the lens. The effect on vision varies according to the area of the lens affected. A common symptom is glare from light sources such as the headlights of oncoming cars. Cortical cataracts vary greatly in their rate of development.

• Posterior Subcapsular:
This type of cataract generally occurs in younger patients and, as its name implies, the cloudiness begins at the very back layer of the lens. Common symptoms are glare and poor vision in brightly-lit conditions and near vision tends to reduce more than distance vision. Posterior subcapsular cataracts can occur as a result of trauma, corticosteroid use and exposure to radiation.

2. Congenital Cataract                                                                                                             

Congenital cataracts are present at birth and occur in 1 in every 2000 births. These cataracts may not affect vision but, if f they do, they may need to be removed. Their cause is often linked to an associated syndrome or to an inherited condition, while in a third of cases the cause is undetermined.

3. Secondary Cataract                                                                                                                   

As its name suggests, this type of cataract occurs after cataract surgery. When doing cataract surgery, the surgeon removes the inner portions of the lens and the outside layer, called the capsule, is left in place to hold the artificial implanted lens. This outer layer may become cloudy and cause visual disturbance, a condition known as secondary cataract. The onset of a secondary cataract can occur within months or years of cataract surgery and is usually present in both eyes. Treatment by laser is quick and usually effective.

4. Traumatic Cataract                                                                                                                  

This type of cataract can occur either straight after, or years after, an injury.  Other causes are by  damage through radiation, electrical current or chemicals or can be due to a disease such as diabetes.