The Single-vision lenses are for those who have problems seeing distant objects. They are also dispensed for those with reading problems.
BIFOCAL LENSES
The bifocal lenses are for those who have problems seeing both distant and near objects. In this case, the patient uses the same part of glasses to solve both problems
ADVANTAGES OF BIFOCAL LENSES
Very easy to adopt to using it
Wider visual field for distance
DISADVANTAGES OF BIFOCAL LENSES
Patient experiences a jump in sight when switching from distance to reading.
The segment for reading is obvious
PROGRESSIVE LENSES
The progressive lenses are also for both distance and reading. But the difference between them and the bifocal is that unlike the bifocals, progressives have no obvious line to separate the distance from the reading portion. The power changes and becomes higher progressively from the top of the lens to the bottom. It changes from distance to intermediate, to reading.
ADVANTAGES OF PROGRESSIVE LENSES
The intermediate section, which the bifocal lack, is a better option for drivers and computer users.
Patient does not experience a jump in sight, when compared to bifocals.
The reading segment is invisible.
DISADVANTAGES OF PROGRESSIVE LENSES
Takes 2 to 3 weeks to get used to
Visual field for distance is narrower
The lens peripheries are distorted, meaning that the vision from the side is blurred.
