Optimizing Light Sources for Vision

Researchers at the Barrow Neurological Institute at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona have discovered that optimizing light sources may assist the human brain in better interpreting visual information. This is good news for people who suffer from computer vision syndrome, as researchers have found that optimally tuning light emitting sources can relieve strain and increase visual comfort.

Flicker Rate

Light emitting devices such as computer  and television screens, light bulbs, and even candles, have a flicker rate. Researchers investigated the way the human eye perceived temporal modulations of light to uncover at which rate vision is most comfortable. As it turns out, the faster a flicker rate, the less the flicker itself is perceived by the eyes, making high flicker rates much more comfortable. This suggests that increasing the brightness of a screen, thus increasing flicker rate, can ease strain without increasing power consumption. A win-win for both your vision and your pocketbook.

Experiments were conducted into two contradictory theories of how bright a light appears: Bloch’s Law and the Broca-Sulzer Effect. While researchers have been studying temporal vision for over 125 years, this was the first experiment to control for all known forms of criteria. The initial findings are encouraging and will be elaborated on as more information becomes available.

Computer Vision Syndrome

Computer vision syndrome may cause symptoms such as:

  • Eye strain
  • Difficulties focusing
  • Blurry or double vision
  • Headaches
  • Neck and shoulder aches

Treating this syndrome is typically done with a combination of glare reduction screens, eye exercises, and prescription eye wear. With this new information from the Barrow Neurological Institute, your eye doctor may now also include adjusting the brightness on your computer, but this is best determined by an experienced ophthalmologist.

If you would like to schedule a computer vision exam to increase your visual comfort, please contact an eye doctor in your area today.

Researchers Test Comprehensive, Inexpensive Vision Screening Device for Children

Children with vision problems can face impaired cognitive abilities and suffer long-term vision loss if not treated at an early age. Yet most studies indicate that between 80 and 85 percent of children in the United States do not receive an eye exam or vision screening prior to entering kindergarten.

Because of those figures—and because even the school-age screenings are typically designed to detect only one or two common vision conditions—researchers at the University of Tennessee Space Institute have created a device that makes pediatric eye exams comprehensive, cost-effective and easy to use. The dynamic ocular evaluation system (DOES) takes about three minutes to use and even less time to train someone to use.

As a child watches a brief cartoon or plays a computer game, DOES employs an infrared beam to check ocular alignment and scan for refractive problems, amblyopia and other potential risks, including major neural problems. The results of the test are available within a minute, and the images and data can be transmitted to a specialist if necessary.

In addition to assessing vision problems, the test can indicate signs of attention-deficit hyperactivity disorder, autism and dyslexia. A clinical test is currently underway at the vision center of a major retailer.

If you or your child needs a vision screening, please contact Eyes.com to locate an experienced eye doctor near you.


Having 20/20 vision is nice. It’s the way your vision should be. Millions of people need corrective lenses to see 20/20 because of myopia. However, these individuals, as well as those who have natural 20/20 vision may find when they hit their early 40s that things that were once so crystal clear up close have begun to get fuzzy. This blurred vision may be more than a passing thing, it may be presbyopia.

Presbyopia is part of aging, and unavoidable for nearly everyone after they’ve reached 40. It’s the reason your grandparents all wear reading glasses, and it’s the reason your parents hold their books and magazines as far away from them as they can.  Presbyopia is, for all intents and purposes, age-related farsightedness.

Why people develop presbyopia is not fully understood, and there are a couple theories. One is that the lens begins to become hard due to proteins. This makes the lens less flexible to focal changes. Another theory is that the ciliary muscle begins to weaken. This makes it harder for the lens curvature to steepen to see things near. A third, and newest, theory is that the lens continues to grow, and by age 40 it has grown so much that the ciliary muscle does not have enough space to contract and steepen the lens. However, this last theory is not held by many eye doctors right now.

Whatever causes presbyopia can only be fixed by the old standbys: corrective lenses, LASIK, and conductive keratoplasty (CK).

If you are 40 or older and have noticed your near vision beginning to blur, find an experienced eye doctor in your area to test you for presbyopia today.

Understanding Visual Acuity

20/20 vision does not mean perfect vision. What it does mean is that you can see at 20 feet what a majority of other people can see at 20 feet. Visual acuity tests are designed to determine at what range you can see. With visual acuity tests, the top number is fixed, but the bottom number is a variable. For example, if you can see at 20 feet what most people can see at 40 feet, your vision is 20/40. The bottom number can go up or down in either direction from 20 and is used to determine if you are nearsighted or farsighted.

Correcting Refractive Errors

If you do not have 20/20 vision, you may require assistance from prescription eyewear such as glasses or contact lenses to help you see objects at a range of distances. Several alternatives to prescription eyewear such as LASIK and PRK can also be used to correct refractive errors and help provide clear sight. In fact, eyewear is not a fix so much as a Band-Aid. Only a refractive error correction surgery can truly provide you with lasting eyesight of 20/20 or better.

If you are experiencing any vision difficulties and would like to learn more about your options, please use the doctor locator at eyes.com to find an experienced ophthalmologist in your area today.