Ophthalmic lenses are generally divided into several categories namely single vision, bifocal and progressive.
Single Vision
- One lens, one power
- General use
-
For presbyopes, lens only provide specific range of viewing distance
Bifocal
- One lens, two powers
- Visible line separates the viewing areas
- Can see near and distant objects in one lens
-
May not be good for intermediate distance
Multi-focal (progressive lens)
- One lens, multi-powers
- No distracted lines (look like single vision lens)
Can see near, intermediate and distant objects in one lens
|