Cloudy vision may be sign of Fuchs' dystrophy

Q. My mother-in-law is 70 years old. She never had a need to see an eye doctor until last week, when she scratched her eye. She found a local ophthalmologist who told her that she has Fuchs' disease, something she had never heard of before.

As a coincidence, I decided since I turned 50 recently that it was time for me to have my eyes checked. Lo and behold, and hundreds of dollars later, I had an exam and was told that I needed glasses. When I asked my eye doctor about Fuchs', he told me briefly about the condition. Can you tell me more?

A. The outermost layer of the eye is known as the cornea. It doesn't contain any blood vessels to nourish or protect it, but it gets its nourishment from the aqueous humor behind the eyes and from tears. Its purpose is to protect the eye from debris, dust and germs. In order for a person to see well, all five layers of the cornea must be free of any cloudy areas. Visual disorders are quite common, affecting about 120 million people in the United States, causing them to wear glasses or contact lenses. The disorders to which I refer are known as refractive errors. They affect the cornea and include myopia (nearsightedness), hyperopia (farsightedness) and astigmatism (uneven curvature of the cornea).