Why is the lens of our glasses have shadow and not transparent


So when I hold my glasses towards wall and put a light source towards it.Even the lens part of the glasses are solid and dont let light through, but then we wouldnt be able to see with it.

In: 0

True the lens is transparent, but its job is to bend light in order to refocus it into your eye. I tried your experiment myself and found if I held the light far away from the wall but held my glasses close to it, the shadow it cast looked like that of an empty frame. But as I pull the glasses away from the wall, the glass portion gets darker progressively. Likely because there is more room for the bent light to be moved somewhere else. Also, when wearing glasses you are usually looking through the lens at a pretty perpendicular angle. Hold your glasses in your hand and rotate them to look through the lens at a shallower angle. You’ll notice the light coming through them is a lot more contorted and there’s more glare.

Edit: typos

Lenses direct the light that falls directly perpendicularly on them to their focus point.

If that light is going to the focus point, it’s not going somewhere else. “Light not being there” is what a shadow is.