I understand how Bifocal Reading Glasses may not seem like the most appropriate place for an extensive discussion on computer glasses, but as more and more people are using a computer on a regular basis this topic is becoming increasingly important. Plus everyone reading this is doing so on a monitor.
Even though more people regularly use a computer, or some other device with a screen, still many people aren’t familiar with computer vision syndrome and its potential long-term influence on your eye health. I hope this is an opportunity for me to provide many of you with an epiphany that leads to greater eye comfort and eye health through using computer reading glasses.
For young people, the most common vision problem is distance vision, thus most people under 40 who wear glasses or contacts are nearsighted. In general, as people age they become more and more likely to become farsighted. Sometimes this can be addressed with inexpensive reading glasses off the shelf, but sometimes the better option is to obtain prescription lenses for near vision correction. The need for bifocal reading glasses arises when someone who was nearsighted in his or her youth also becomes farsighted as he or she ages.
Most bifocals prescribed for people beyond the age of 40 — often prescribed because they’ve developed presbyopia — correct far and near vision. Yet these bifocal eyeglasses do not provide an appropriate lens for the distance and eye activity involved in computer work. Some people believe trifocals and progressive lenses — both of which provide a portion of lens for intermediate distance vision — can be utilized for computer work. However, these lenses don’t provide nearly enough surface space to ease and protect eyes for extended periods of computer use.
Many computer users will suffer headaches, eye strain, dry eyes and blurred vision if they do not utilize appropriate computer reading glasses. Such symptoms indicate computer vision syndrome. These problems compound themselves with further issues when computer users without computer glasses attempt to adjust for their strained eyes or blurry vision by tilting their head to view the monitor through the bottom of their glasses or by excessively leaning towards the monitor. Such behavior leads to sore back, shoulders and neck problems.
You really should address your vision care just as you monitor your blood pressure. This includes regularly using sunglasses or even bifocal sunglasses as well.
It is important to appreciate that this is not just about comfort. Besides increasing the likelihood of developing presbyopia and asthenopia earlier or in more severe forms, inappropriate lenses — or lack of computer glass lenses entirely — can significantly decrease worker productivity and accuracy.
The University of Alabama School of Optometry conducted a study in which they examined a large number of diverse computer users between the ages of 19 and 30. Their vision was carefully measured before, during and after the study.
Subjects were randomly provided either correct computer glasses or a “placebo” in the form of non-corrective glasses. They were then assigned to perform a number of jobs involving a variety of different font sizes on both CRT (the old, large monitors) and LCD (the newer flat, shallow monitors) computer screens.
Subjects were timed and their performance was recorded and measured for accuracy. Individuals with inaccurate or non-corrective lenses which were not designed specifically as computer glasses experienced a 9 percent decrease in productivity and a startling 38 percent decrease in accuracy. Even people who described no discomfort or experienced no problematic symptoms were tested to have significantly lower productivity and accuracy scores.
Computer Vision Syndrome (CVS) represents a category of eye fatigue symptoms. It is a relatively new condition, and unsurprisingly, its increased occurrence parallels the rise of computer usage. The symptoms may vary in different individuals, from many symptoms to very few, with some people experiencing terribly painful symptoms to others who simply develop what they consider minor annoyances. CVS has been known to be diagnosed in both children and adults. Currently it is believed that specially designed computer reading eyeglasses can provide measurable relief from these computer usage symptoms (especially headaches). You can even find computer glasses, and bifocal computer glasses, that are lightweight rimless glasses for greater comfort.
Eye strain from computer usage and computer vision syndrome results from human eyes and brains functioning differently when reading letters and numbers on the printed printed page than they do reading letters and numbers on a computer monitor.
Human vision requires much less effort to maintain easy focus on the dark black letters with defined edges of print. However, even newer, higher resolution monitors do not provide the same contrast and definition of the printed page.
Letters on a monitor are formed by pixels (think of pixels as tiny little light bulbs). Dozens to hundreds of pixels are required to render even a single letter or number. The breaking up of characters into these separate pixels creates difficulty for our eyes to maintain consistent focus. Rather, human eyes fade their focus to the Resting Point of Accommodation (RPA). Human eyes involuntarily reduce focus to RPA and then strain to sharpen focus on the monitor.
Whether we realize it or not, this occurs continuously as we work with computer monitors. By constantly flexing the focus muscles of our eyes, we develop fatigue and strain both in our eyes and in the muscles around our eyes. Moreover, this action also greatly decreases our blinking reflex while focusing for long hours of work on computer monitors. So it is important to reduce eye strain as much as possible.
Our eyes’ normal blink rate is about 15 to 25 blinks a minute. Several studies have indicated that extended computer usage results in a decrease of blink rate to as low as 5 to 7 blinks per minute. In addition to placing a strain on the ciliary muscles of the eye, this causes dry eyes. Besides blinking more find other tips for relieving dry eyes in this article: Dry Eye Relief
After a while, this will induce indications of asthenopia and provide a feeling of weariness excessive to the amount of time spent working. Many individuals describe an inability to focus on near objects for a short while after they stop working on the computer screen. This is most observed in individuals between the ages of 30 and 40. It represents a decrease in the adjusting focusing mechanisms of an individual’s eyes. Unfortunately, this may also lead to developing presbyopia earlier.
You will experience some form of computer vision syndrome if you consistently spend more than two hours a day using a computer. Early CVS symptoms include the following:
- Focus difficulty
- Weary eyes
- Burning eyes
- Blurry vision
- Doubled vision
- Shoulder & neck discomfort or pain
Thankfully, there have been several special purpose lens designs developed specifically as computer reading glasses. But note that these eyeglasses have been developed for computer use and thus are not appropriate for general use or driving.
Simple computer glasses feature a single vision lens with a power prescribed to provide the most appropriate vision for the distance of a user’s computer monitor. This lens design reduces the amount your eye must adjust to keep characters on a computer screen in focus and also provides the largest field of view for moving your sight around the computer workspace. This significantly reduces contorted posture, strain to the eyes and blurred vision. These kinds of lenses are often prescribed effectively for both older and younger users.
Among computer users with presbyopia, the occupational progressive lens has become a very popular form of computer bifocal glasses. This lens is a no-line bifocal lens, or multifocal lens, which corrects near and intermediate vision very well and distance vision in a limited fashion. It is designed with a much larger intermediate zone than usual progressive lenses for more effective accommodation for computer use. Because of the limited distance vision correction, these lenses are not appropriate for distance vision tasks such as driving.
You will also find lined trifocals with a larger intermediate zone than normal trifocals. However, these are decreasing in popularity because of the number of lines on the lens. A common compromise lens is the occupational bifocal. In occupational bifocal reading glasses, the upper lens is for intermediate vision (computer use) and the lower lens is for near vision (reading).
In recent years, computer reading glasses have become available as clip-on attachments for normal reading glasses.
Remember that computer glasses do more than just help your eyes! As part of a proper ergonomic setup, computer glasses can also assist you to resolve computer-related headaches as well as neck, shoulder and back pains resulting from straining your eyes as you work at your computer.
Thank you for visiting Bifocal Reading Glasses and I hope you’ve learned enough about computer glasses to improve your future comfort and health!