Thanks Jim, As always, you have posted something so useful. Prem has a lot of trouble with his vision and the neuro-ophthalmologist whom we consulted said that his double vision was due to the Parkinson's. Apparently he has a squint that can be either in one eye or the other so no correction, such as with a prism, is possible. He too suggested covering one lens of his reading glasses while reading. Prem is trying to get accustomed to that. I imagine, though, that he will find it difficult to cope with three different pairs of spectacles, however excellent the suggestion. Thanks again. Moneesha Calcutta, India ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn