Why You Might Need Two Powers in One Lens
After roughly age 40, most people begin to notice that reading requires holding materials at arm's length. This condition — presbyopia — is caused by the natural stiffening of the eye's lens over time, reducing its ability to change focus between distances.
Bifocals: How They Work
A bifocal lens has two distinct zones separated by a visible line: the upper portion for distance correction and the lower portion for near (reading) correction. There is a sharp, abrupt transition between the two zones. The optics are precise and predictable, and many longtime wearers appreciate this clarity.
Progressive Lenses: How They Work
Progressive lenses provide a gradual, seamless transition from distance (top of the lens) through intermediate (middle) to near (bottom). There is no visible dividing line, and there is a range of intermediate vision that bifocals lack. However, an adaptation period of 1–2 weeks is common, and the reading zone in the lower portion is narrower than in a bifocal.
Which Should You Choose?
- Choose bifocals if: You primarily need distance and reading correction, budget matters, or you have tried progressives and not adapted to them.
- Choose progressives if: You spend significant time at computer distance, prefer no visible lines, and are willing to invest in a quality design and fitting.