NHS cataract information for patients and follow the relevant links
If you follow the link to
causes you'll see different reasons for the growth of cataracts from as ramrod points out, diabetes to eye injury...... and of course the most common reason is ageing...... but since that isn't likely to be the cause of yours, i'm sure your G.P/Optician will or at least should follow through with other tests, and if not....... ask for them