Spectacle Lens Types
The optical surface or design imparts the optical correction to the material. Given
the infinite number of eyesight corrections, the numbers of designs is almost infinite.
BIFOCAL LENS:
Description: The lens has two separate correction areas. A segment
of the lower half corrects for near vision; The rest of the lens corrects for distance
vision.
Correction:
Myopia,
Hyperopia (hypermetropia) and
Presbyopia
PROGRESSIVE LENS:
Description: The power varies in a progression from distance vision
in the upper part of the lens to near vision in the lower part, with no break in
optical continuity. A single pair of glasses enables the user to see at all distances.
The most effective correction for presbyopia.
Correction:
Myopia,
Hyperopia (hypermetropia) and
Presbyopia