New answers tagged eye
I heard a few times that using them as sunglasses is hurting the eye since UV light is not filtered, but the pupil is wider than it would be w/o wearing them because the visible light is dimmed. IFAIK, there is no evidence for this claim. See this paper (unfortunately, it's behind a paywall): The supposition that, because of pupil dilation, there ...
No, it's not diffraction. It's because you increase the depth of field by reducing the aperture. Basically, the more concentraded the light is, the better you see a defocused images. See this question: Why apperture affect depth of field in photography?
Top 50 recent answers are included