We reach the age of 40-45 and suddenly it seems like the writing on the shampoo bottle has been printed smaller. For most this seems to be the time when changes in our vision start and new vocabularies need to be learnt. Enter bifocals or readers if you've never worn glasses. (but that's a different thing altogether)
Once the emotional struggles are over, for they seem to be present whether you wear glasses or this is your first foray into the "need to see better" arena; you will need to purchase either reading glasses or bifocal eye glasses.
Some say that bifocal lenses were invented by Benjamin Franklin ,but regardless of who invented them it's a clever solution for being able to have a multifocal lens. Lens that can help you see up close or far on the same pair of glasses. This would mean there is a magnifying power at the bottom of the lenses (for help reading) and whatever power you normally need on your glasses at the top/middle of your lenses for seeing far. This idea of having two prescriptions on one lens, with a separating line is called bifocal lens.
There is a little learning curve once the glasses are worn. Most people tend to lower their head when they are reading something, maybe in an attempt to get closer. Well here one needs only move the eyes down without moving the head...just lower the eyes and we will then have available the magnifying power of the lower portion of the lens.
This is the trick, we must relearn to look down with the eyes and not lower the head. The eyes then will refocus and use the new correction power available.
For some people this refocusing may cause them to experience dizziness or even headaches. But this will go away if it persists then one must revisit there eye care doctor.
Another option without a dividing line, but with multifocal lenses that blend into each other is progressive lens.