I was on HCQ for RA with cutaneous vasculitis and it was spectacularly effective, dropping my blood scores into normal range.

But I also got severe facial hyperpigmentation after only 10 weeks, looking like I was wearing lipstick, eyeliner and had two black eyes as if I'd been in a boxing match. I don't think it's any coincidence, since both are caused by melanin binding with HCQ, that it went for my retinas too and I lost saturation in the centre if looking at something red. (I was testing with an A3 sheet of red card)

I wasn't going to wait for it to show on scans, that damage can't be repaired and sometimes progresses after the drug is stopped, so I stopped taking it.

I am a very rare case but a walking example that it can damage your eyes very early on, with no symptoms.