Blurred vision is not among the more common side effects of chemotherapy. However, according to the American Cancer Society's literature on side effects, there are certain chemotherapy drugs that might
cause this problem. Some chemotherapy drugs can damage the cranial nerves, which in turn can cause blurred or double vision, as well as hearing loss or ringing in the ears.
Of course, blurry vision might also be occurring because of a problem in the eyes itself, such as macular degeneration. And chemotherapy would not cause scarring under your eyelid. There many other medical conditions that can cause blurred vision as well, some of them serious, so it's important to talk to your doctor about this problem as soon as possible, and get it checked out.