More than Just 20/20
It’s hard to believe the kids will be going back to school in less than a month! Most parents have a long checklist of things to do before that day, but here’s why a comprehensive eye exam needs to be on that list.
Did you know that up to 80% of what a child learns is presented visually? But it’s not just seeing 20/20 that matters. Our visual system actually has three levels: visual acuity, binocular vision, and visual perception.
Visual acuity is a measurement of the clarity or sharpness of what you see. This is typically what is focused on during most vision screenings. It is important to determine that each eye can see equally well, both at distance and up close. However, just because each eye can see 20/20, doesn’t mean that glasses aren’t needed.
Imagine your 40-pound child wants you to hold her. You might be able to do that relatively easily. Now think about carrying her around all day, never setting her down. Your arms would get tired, right? This is similar to being farsighted, a common condition in children. Farsightedness generally means things are clearer far away than up close but your eye muscles have to focus to keep things clear. Those muscle are working all day long just like your arm muscles would be if you were carrying something heavy. Eye muscles, just like biceps, get tired!
At a comprehensive eye exam, your optometrist determines if there is any refractive error present, such as nearsightedness, farsightedness, or astigmatism. This can actually be determined without any input from the patient (so no cheating!) Of course, the more reliable information the patient can provide, the more comfortable they may feel with the prescription.
For more information about the differences between a comprehensive eye exam and a vision screening, click here.
Binocular vision is a function of how well your eyes work together. In order to achieve the best binocular vision, first the best visual acuity must be obtained in each eye. Once the eyes are both seeing well, then they can work together.
Binocular vision can be assessed in many ways. First, it is necessary to determine that the eyes are both pointing in the same direction. Some eye turns can be obvious, but some can be much more subtle. Next, we determine the eyes’ nature posture (phoria). Some eyes like to drift out or in, but when the eyes are focused together, the ocular muscles work to keep the eyes pointed at the object of focus. Another way to check that the eyes work together is to test depth perception. Think of 3-D movies or Magic Eye™. In the exam room, we use special glasses to test if a patient can see an image jumping off a page. If one eye is out of focus or not looking in the same direction, the image appears flat.
There is so much more to good binocular vision than we have room for in this short article. However, if you know someone who struggles with reading, eyestrain, double vision, or skipping lines, these may be symptoms of a binocular vision problem. Call your optometrist for help!
Visual perception is the ability of your brain to interpret what your eyes see. As you may have guessed, this is crucial for learning. There are several skills that all work together to form good visual perception, including visual memory, visual sequencing, spatial relations, and foreground-background differentiation. A child with poor skills in these areas may show delayed reading skills, the inability to visualize past experiences, and poor hand-eye coordination. These students may have to work twice as hard as their peers because visual information that is helpful to others, may be distracting to them.
I encourage all parents to schedule eye exams for their children every year. Not only do kids’ eyes change quickly but it can also be hard to tell if your child isn’t seeing their best. Some kids don’t know that the way they see isn’t right. Call us today to schedule your child’s comprehensive eye exam!