Dx - optic nerve hyperemia. blurred vision in left eye for more than a year. possible causes? can be from use of zaditor (ketotifen) for allergies?

Ophthalmologist : Make sure you see an ophthalmologist for evaluation. You may have congenital blurring of optic disc, disc drusen, hypoplasia, but with the blurred vision, I'd be worried about something different. A year-long history without worsening is not typical of inflammatory optic neuritis. Compression of nerve by tumor? Zaditor™ is not the cause. See an ophthalmologist.