Hello again and thanks for waiting.
I have worked out an answer for you below ...
1. Very often cataracts or other changes in the lens in the eye are age related but as long as she can get about OK then it is often not too much of a problem as often the disease advances very slowly. However it can also be associated with other diseases such as diabetes but your vet will have considered that.
2. Dawn washing up soap does have a limited effect in terms of flea control but my experience is that as a wash it is very safe indeed, so much so that it is often used for very young puppies and kittens which are too young for conventional flea treatments. I would very much doubt if you would have any problems with using it as wash in an adult dog, this is a very safe product.
3. As far as flea control goes something like Frontline would be good on your pets but it is also important to spray the apartment with a suitable product to kill fleas and flea eggs in the flooring and furniture at the same time otherwise the fleas will just come back. You can get these from your vet or better pet stores.
4. I guess the squinting is your main concern. Sometimes this is caused by the cataracts becoming more advanced but there are also a number of other acute eye diseases which can cause this. It is so difficult to comment on this unless you can get a good look at the eye through an opthalmoscope, so really if the squinting continues you would be best to have your vet take another look.
I hope I have covered your question fully enough but if you would like further clarification or to talk things over a bit more then I will be on-line for the next hour or so and I will be more than pleased to continue working with you.
Please be kind enough to rate my service to you after we have concluded our dialogue, such feedback helps me maintain the quality of my answers.