Bifocal Glasses – When do You Need Them?
Bifocal glasses have the lenses with two powers meant for near vision and distance vision. The upper segment of the bifocal glass has power which corrects distance vision. The lower segment of the glass corrects near vision. When we read something, for instance, we look down and see through the lower segment of the glasses. When we look into distance, the line of sight passes through the upper segment. How are bifocal glasses different from [...]