Bifocal Glasses - Do You Need Them And If So, When?

Franklin created this unconventional set of spectacles using one set of very convex lenses as the lower half to allow for clear vision when viewing close up objects and one set of less convex lenses for viewing objects farther away.

These glasses continued to be made with two separate lenses fitted into the frames until the 20th century. Bifocals were somewhat problematic for many users because this method of construction made them very fragile.

A method of fusing the two lenses was developed around 1900 and to this day, some bifocals are made using this fused lens technology.

However, a more common method used today is setting a reading lens (for close up viewing) into a lens of a different prescription which is designed for longer range viewing or correcting astigmatism. The reading lens can be made in a variety of shapes and sizes, depending on the needs and tastes of the wearer.

Vision Problems Solved By Bifocals

Bifocals are generally worn by people who need to correct myopia (nearsightedness) as well as another vision problem simultaneously.

The two different prescriptions of lens used in bifocal reading glasses allow to see objects which are close up with clarity while at the same time correcting for:

- myopia
- presbiopia
- hyperopia (farsightedness)
- or astigmatism

There are many different configurations of bifocal glasses available to suit the needs of people with different visual impairments.

You can get bifocals:

• made for people who spend a great deal of time looking at text close up (such as those who work in offices and spend much of their work day looking at a computer screen);
• and made for those whose needs for close up viewing are less intensive.

Read more about bifocal reading glasses for computer use.

Getting Used To Them

Bifocals work well for many people with multiple mild to moderate vision problems which can be addressed by corrective lenses. However, these glasses do take some getting used to as you could expect.

• At first, the switch from one lens to another can cause headaches and nausea in users, though viewing the world through two different lenses soon becomes second nature.

• Like any corrective lenses, using bifocal reading glasses requires the wearer to retrain their eyes to seeing in this new way.

• Bifocal wearers have to become accustomed to the relatively small field of vision they offer for reading, though again, this is something which most wearers rapidly come to terms with.

The technology behind the manufacture of these two in one spectacles continues to improve, with new and better designs being available every year.

Bifocal glasses may be an older optical technology, but they have come a long way since Benjamin Franklin's first pair in the 1760s and get better and better all the time.



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