Some blind people where sunglasses because their eyes look a little different, also with sunglasses on it isn't obvious to others they are sightless. That's all I can figure anyway.
Ok. But, isn't it more likely a sighted person says to the blind, "Here, put these on"?
And, it occurrs to me that a seeing eye dog, or a long white cane just might tip off a sighted person about an individual being blind despite the dark glasses?
And, why is it you wouldn't want others to know you are blind? Perhaps there is a greater chance someone will toss you the keys to their vehicle.
Which reminds me. Did anyone else see the Top Gear (US) show where an actual blind man won a "drifting" competition against two other sighted young men, all of them driving Nissan 350Zs, I think?
Cheers,