one of my dogs had cataracts and in one eye the retina has become detached so he has lost the sight in that eye completely. in the other he has a lot of scar tissue due to the cataracts and can't see out of it due to the scar tissue, so is blind. he copes really well but he can have an operation to have the scar tissue removed. BUT if the operation doesn't go right, he would lose the eye completely (i.e have to have the eye removed) and would have it permanently shut. is it worth him having the operation? what do you think?