I had visual disturbances, too, and completely forgot about that aspect until you mentioned it now. i.e. I would be driving somewhere and stop at a rest stop half way. (on a two hour trip)
Still sitting in the car, I would watch this couple get out of their car, and to my surprise, this was the couple who I was going to meet with and who were flying in from the south and had absolutely no reason to be there. Then I would look to the other side and watch another couple get out of the car, and again, the same people who had just gotten out of the other car on the other side were now stepping out from another car. (none of these people were who I thought they were but they all looked identical) Then I would look ahead of me and this time my neighbor was leaving the restrooms.
I also, more than a few times, would walk up to someone in the supermarket thinking, or better sure, they were someone I know and start talking to them with this belief, when they were total strangers.
There were also other weird visual things but I cannot remember them clearly, more like small hallucinations.
Hope this helps a little, but in my case it did mostly go away at some point .
KATRIN (although I still have some visual hallucinations, and/or that I think something is moving)
I am very sorry that you are now having visual problems and major depression, in addition to having had to go through all those treatments for breast cancer!
I'm sure your doctors must have reviewed the side effects of the chemo drugs you were given, and of any medications that you might be taking for depression.
The things I would think of in regard to side effects is that dexamethasone (Decadron), which is often given along with chemo, to prevent allergic reactions can cause vision problems. (It can increase eye pressure and exacerbate glaucoma.) Also, several of the chemo drugs can cause unusal bleeding, which would raise the question in my mind of whether this could could possibly lead to retinal damage of the type that diabetics may experience.
However, you mentioned in another post the you have been examined by a neurological ophthalmologist, so anything of this nature should have been detected.
I hope you your depression will improve in time, although it may require both medication and pyschotherapy, to help you deal with all you are going through. I also hope that you will eventually find an answer to your vision problems, but if not, that you may someday be able reach acceptance of that loss as NOT too great a price to pay for treatment that may have saved your life...
Best wishes...