

The source is some old “Top 10 Oldies Myths” article from About.com. Never cite wikipedia. Cite the source. https://web.archive.org/web/20140711194805/http://oldies.about.com/od/oldieshistory/a/oldiesmyths.htm
And that source doesn’t say anything about light sensitivity.
Roy did have eyeglasses to correct his vision, but they were quite normal; en route to an Alabama concert, however, he accidentally left them on the plane. The only other pair he had were prescription sunglasses, so he wore those instead. The very next day Roy was scheduled to open up a European Beatles tour, and there was no time to go find his old pair, so the dark shades stayed on him throughout the tour. The resultant frenzy of Beatlemania ensured that the singer would be seen throughout the world in that pair; by the time he returned home, it was a trademark.
Not that I necessarily believe anything in such an article.
In all my years, I’ve never heard a single person say they ever thought he was blind. I have a really hard time believing this was ever commonly believed.
I’m not disputing that you might have believed it and that some other people might have believed it, too. It’s just, I doubt it was a common thing.
That sounds like it’d be Futurama joke.