A summary of lesser-known eye conditions, but including those that affect a surprising number of people, together with the lens types that can reduce their effects.
Details of chronic eye conditions
Aniridia is the absence of an iris, which is the coloured part of the eye.
Most cataracts occur later in life. In some rare instances a child may be born with cataracts or develop them early in life. These are known as congenital or paediatric cataracts.
Corneal dystrophies are a group of conditions that are genetic in origin and cause the normal metabolism of the cornea to not operate normally. These may or may not cause symptoms (asymptomatic). Some are progressive in nature and may produce both visual issues and discomfort.
In keratoconus, the cornea, which is the clear dome-shaped structure at the front of the eye, bulges forward making the surface of the cornea irregular in shape and distorting vision through the affected part.
A pinguecula is a small yellowish lump that forms normally at the edge of the cornea at about 3 or 9 o’clock. They normally appear in middle age and can be exacerbated by exposure to sun, or dry and dusty conditions.
Often confused with a pinguecula, a pterygium is a growth of white tissue from the conjunctiva, or white of the eye, that protrudes into the cornea.
In trichiasis the eyelashes turn inwards and irritate the cornea and conjunctiva.