In this article, you will learn why bifocal glasses might not work well when using a computer. Bifocal lenses have two separate areas with one prescription for distance vision in the upper half of the lenses and another usually a little smaller part with the added reading power. In between both areas is in most cases a visible line. Those lenses should not be mixed up with progressives which have no visible line.
When the needed reading power is higher than 2.25 (Add) you might not be able to see the PC display clear whether with the upper nor the lower half of your bifocal lenses. The reason is with an increase in needed reading power the distances you can see clearly in will be changed. For example, when you can not focus properly on the distance of your computer monitor within your arms reach you need to increase the reading power a little to be able to see clearly again.
When the computer monitor sits 31.5 inches/ 80 cm in front of you an added reading power of 1.25 Diopters is needed maximally so you can see clearly on your display. But when you need more than that additional reading power to be able to read in distances closer to you let us say 2.25 Diopters you can read-only in a distance which lays 17,3 inches / 44cm in front of you.
Especially wearers of bifocal lenses might have a hard time using their glasses on a computer because of the mentioned issue they would need to increase the distance to the screen when looking through the upper portion of the lenses. And when they tip their head back to look through the reading area they would have to go in a position that is uncomfortably near in relation to the computer screen.
Fitting Issues With Bifocals for Computer Use
Despite the fact mentioned above that people will have a hard time with an Add value higher than 2 Dioperts bifocal lenses provide you with an unfortunate position of the added reading power in front of a monitor.
Let us think about the position where the reading power is located. The upper part where the visible line is located on bifocal lenses is positioned directly in front of your lower lid. This way you will only get the reading support when you look down through the lower half of the lenses. While this might work for a laptop this will not work with a regular desktop computer.
You would need to tip your head back again in an unnatural position to be able to use the reading power in your bifocals. And in addition to that, this will only work when you are a little younger and the needed reading power is not as high. When you are 48 years old and you need a reading power of 1.5 diopters you will be able to read at a distance that is maximally 25inches / 67cm in front of you.
Before You Buy Bifocals Make Sure To Know Where You Want To Use Them
As you read in the paragraphs above distances you can read in is dependent on the ability to focus on near objects and therefore the additional reading power within your bifocal lenses.
When I do consultations for my clients in our optical shop I oftentimes need to clarify the terminology a bit. Because when you talk about your computer do you mean you check your emails on your tablet? Because this would probably work. When you talk about the laptop depending on your prescription this will only work with bifocals when you need less reading power. If you mean a real desktop environment when talking about computer use would probably have to switch to another pair of glasses specifically made for the distances in your desktop environment.
Oftentimes when people decided to buy bifocal glasses and they already heard and saw during the consultation the glasses might not work well with their PC they still want to test things out on their own. Of course, this is totally ok but when they leave with their new glasses I usually give them a form where they should fill in the distances in your desktop environment. So when they come back I can fine-tune the new computer glasses to the noted distances.
In some cases, the second pair are also bifocals with an increased lens power in the upper half of the lenses and the full reading support in the lower half. This way the PC screen is perfectly clear as well as the reading distance. But in most cases, people buy additional computer glasses when normal bifocals do not fit well with their working environment.
5 Signs You Should Not Use Bifocals in Combination With Your PC
- You need to position yourself in an unnatural way in front of the monitor to be able to see clearly
- You get shoulder and neck problems when using your bifocals during PC work
- You have a hard time staying focused during work
- Your Bifocals let you see sharp in the close range but not when you look up at the screen
- Bifocals can lead to dizziness and headaches when they do not fit your work environment
Due to a variety of reasons bifocal lenses are good all-round glasses. But when they are optimized for doing a lot of things good they will have their shortcomings in a few situations. In those situations, you will benefit from a second pair of glasses. Especially when you are using a PC for a couple of hours daily you should consider an additional pair of glasses because bifocals will not be ideal.
Alternatives are computer glasses or reading glasses fine-tuned to the needed distance with your PC or laptop. When you think you know the distance from your PC to your eyes make sure to not gauge but measure it. Tell the optician the distance and he or she will be able to show you directly with the testing frame before buying your bifocals if one or another option will work best for you.
I wish you a great day.