Keratoconus is a condition that runs in families. It is caused by a progressive thinning of the cornea of the eye, causing it to change in shape from dome-shaped to look more like a cone. It is sometimes associated with atopic dermatitis, a type of inflammatory skin disorder that results in an itchy rash. Because of the varying thickness of the cornea, a person with keratoconus has distorted vision.

If you have keratoconus, you may not be able to achieve perfect vision even if you are prescribed glasses. Contact lenses, although they can be used, can sometimes make the problem worse. This is because rigid contact lenses are needed to allow good vision, but they may irritate the inflamed conjunctiva and unfortunately you may find your vision has worsened when you stop using the lenses. Talk to your ophthalmologist about your particular needs if you have been diagnosed with this condition.

Along with keratoconus, atopic (allergic) cataracts may also be associated with atopic dermatitis. Doctors estimate they occur in about 8-10 per cent of people who have a severe form of atopic dermatitis. Atopic cataracts mostly occur in children and young adults.