Assuming cataract surgery, the surgical procedure is the same that is done in people. The procedure has advanced over the years and is routinely done in people, I had both my eyes done in December. The diabetes is a little complication, but no a reason not to do the surgery.
The question is: will this really improve quality of life? Most dogs adapt and do quite well without the surgery. They don't need to have the visual acuity that we do to read, drive or just do day to day activities. The gradual development of the cataracts make the adjustment easier and most don't show any distress with the partial loss of vision.
Doug, DVM