The myth about 20/20 vision

Many of us are familiar with the eye chart that is used to measure "visual acuity." A 20/20 visual acuity is an arbitrary standard of what size letter most people who didn't need glasses could see from a distance of 20 feet. However, many people who have 20/20 eyesight still struggle with reading and learning.

The myth is that 20/20 eyesight is not enough. In fact, having perfect eyesight is only a very small part of what defines perfect vision. Vision depends on approximately 20 visual abilities that an eye chart cannot detect. However, sometimes, professionals whether it's a school nurse, a pediatrician, or an eye doctor, refer 20/20 eyesight as perfect vision. That is why many patients and parents of patients who were told that they (or their child’s) vision is perfect are still having problems in school, work and with prolong near tasks. It all depends on how the professional defines "perfect vision".

Vision depends on both visual motor skills and visual perceptual abilities. Visual motor skills refer to eye tracking, eye focusing and eye teaming proficiency. These skills are necessary in activities of daily living, such as reading, playing sports and driving. Deficiency in visual motor skills cause reading problems such as skipping of words/lines, poor comprehension, headaches around the eyes, double vision and/or fluctuating blurry vision (see symptoms checklist for more details).

Visual perceptual skills refer the ability to process, interpret and understand visual information. For instance, visual discrimination, visual memory, figure-ground, visual processing speed, spatial relations, form perception and laterality/directionality are some of the skills important for spelling, math and efficient learning as a whole.

Furthermore, vision is important in guiding movement in space and eye-hand coordination. This is why professional athletes such as NFL player Larry Fitzgerald and NHL player Chris Higgins engage in sports vision therapy.

In reality, you can have 20/20 eyesight yet still have vision problems that affect learning. Patients of all ages can have 20/20 eyesight, yet benefit from optometric vision therapy for visual problems having more to do with insight than eyesight. While most processes related to eyesight occur in the eye, most processes related to vision occur in the brain. Seeing a line of print doesn't do you much good if you can't visualize what it means.