Excellent point Allan. I've also been asked this question many times and have have never been able to provide a definitive answer.

I only became a full time spectacle wearer in my 40's though I have worn clear safety glasses in various roles previously and also appreciate the alteration in perception. I'm looking forward to an answer from someone who specialises in this area for my own information.

Andy

I too have been asked this question and am myself a wearer of prescription lenses. On visiting my optician once, I asked her if there was anything in it. Her answer was (approximately) that it was unlikely that a “clear” lens could cause deterioration in eyesight or strain or headaches. It was, however, more likely that the individual was simply noticing their own prescription. When you think about it this makes sense. There are plenty out there who are borderline when it comes to needing prescription glasses. Many people squint their way through the eye test to avoid “needing” glasses. There is no change in the orientation of the light passing through "clear" lenses, I feel the birth of a new myth.

Further to this I would have though that if there was something in it, the sunglasses industry would have picked it up by now. I’d be surprised if there wasn’t some hard research available one way or the other. I’ll leave it up to someone out there to find…I’m off to find an eclipse to test these cheap sunglasses.