Glare refers to the difficulty in seeing, in the presence of bright light. This bright light can either be:
- direct - shining straight through a spectacle lens
- indirect - light reflecting off the spectacle lens.
As such, glare can be reduced in several different ways. It can be reduced simply by having a tint (or polarizing filter) in the spectacle lens which cuts down on light passing through the lens. Apart from that, you can have a special anti-reflective coating that reduces light bouncing off the lens into the eye.
As you can see, calling a lens 'anti-glare' could possibly have different meanings.
I personally think that if a person will be wearing a particular pair of spectacles most of the time, it is helpful to have an anti-reflective coating on the lens. This will help whenever you are in a situation where there is a bright light shining from behind you, whether this is from artificial light or an open window.
With respect to tints, this is a very individual decision and has to be balanced with the usual environments the glasses are usually worn in. Too dark, and it gets difficult to see when the lights are out. Most of the time, tints are not necessary.
A special case would be 'Transitions' glasses which turn dark in bright light-these can add convenience in removing the need to have separate pairs of sunglasses.
