What are bifolcals?

Question

i know they are glasses - just what kind?

and what do you call glasses that don't hinder your eyesight?

Answer 1

Bifocals are lenses that give 2 focal ranges, hence the name bi-focals. Take a look at a grandparent's glasses and if you can see a small half circle that is straight on top, in the lower portion of the lens, that's a bifocal. ( some can be completely round, but somewhat obsolete now).

The need occurs when someone needs to see in the distance and also up close, and this is more convenient than having 2 separate pairs of glasses.

More people now use progressive lenses, which aren't bifocals. They are multifocals that give different focal ranges for the wearer. With the use of computers, progressives offer people that distance, where standard lined bifocals don't. Unless they are specifically for the computer.

Answer 2

bifocals are glasses that have reading and distance glass in one lens

Answer 3

They are glasses that have different power. The bottom of the glasses have one power and the tops have another. They usually have a line across the glass.

Myself, I wear progressives. Higher power at the bottom and lower power at the top with no visible line.

As for glasses that don't hinder eyesight I guess would just be plain glass lenses.

Answer 4

Bifocals are lenses that have like a magnifying glass on the bottom of the lens which makes small print look bigger - there are different strengths like you see at stores 150's are the lowest. some people get them blended into their glasses so you don't see the bifocal line, the upper lens are  for watching tv or driving and the bottom lens is for reading.