The department of motor vehicles, the school nurse and the pediatrician use vision screening to identify vision problems. Screening usually involves standing a given distance from a lettered chart, covering one eye and reading down the chart to the smallest letter possible.
According to a recent study in Australia, researchers found that results for detecting myopia in 12 -13 year olds was nearly 98%. Good news for the nearsighted, but not so good for the tweens with astigmatism or hyperopia. Only half of the hyperopic children were identified by the vision screening and 25% of the kids with astigmatism were missed.
Screenings are best designed to detect problems with distance vision, and that is important for children socially and physically, but myopia represents the least risk for reading and learning. A myopic child is more likely to notice that the board is blurry and move to the front of the classroom. Hyperopia on the other hand, makes it more difficult to see things close up and astigmatism effects vision at all distances. Children with uncorrected hyperopia and astigmatism will have more difficulty reading and writing and may not even be aware that the difficulty is due to his or her vision. These are the children that may complain of headaches, avoid reading and school related tasks.
A vision screening test identifies some vision problems, but can miss disorders that have a profound effect on a child’s ability to succeed in school.
Last time I wrote about the value of having a baby’s eyes examined. Now I will address the question of how do you check a baby’s eyes?
Obviously an infant is not able to read the letters on the eye chart or perform subjective tests such as selecting the clearest image. An example would be when I ask “which is better 1 or 2” question. Fortunately, there are other ways to determine visual acuity. Measurements of visual acuity and refraction are intended to identify nearsightedness, farsightedness and astigmatism. All are risk factors for amblyopia. Amblyopia is caused from non-use or deprivation that negatively impacts the development of the visual system. Instead of an eye chart with letters that I use on school age children or a chart with shapes that I would use on a preschooler, I use a preferential-looking technique. Humans prefer to look at interesting objects instead of plain ones. I have several paddles with different size gratings and one paddle that is only gray. I flash the paddles in front of the infant and watch his/her response. This tells me how small the baby can see at a given distance. The smaller the gratings, the better the acuity. If the baby doesn’t prefer the gratings to the solid gray, I know we have passed the acuity threshold.
Retinoscopy is the other technique I use to measure the refraction, how much correction is needed for the baby to see clearly. Retinoscopy is the same technique my staff uses to get a starting prescription on most of my patients. They use a computerized system that measures the light as it comes off the retina (back of the eye). I do the same thing for the babies, but with a hand-held scope and some lenses.
Other assessments for eye alignment, motility and binocularity are done with various penlights, small toys and puppets. These tests measure eye coordination, which is the ability of both eyes to work together as a team to create one three-dimensional image in the brain. Good eye coordination, a skill that is not innate and must be developed, keeps the eyes in alignment. Later in life, poor eye coordination can make reading for extended periods of time difficult and may result in avoidance of detail work, such as writing or artwork, poor reading comprehension and clumsiness.
To evaluate the overall health of the baby’s eyes I dilate the pupils. The dilation causes little to no discomfort for the infant and allows a much more thorough examination. With light and magnifiers I can see the anterior eye structures like the cornea, lens, lids and lashes and the posterior structures such as the retina, optic nerve and blood vessels.
As an InfantSee provider, I provide a complimentary comprehensive eye assessment to all baby’s less than a year. (Nine months old is perfect for the exam).
When I bring up the discussion about examining an infant’s eyes, I am asked 2 questions:
Why should I have my baby’s eyes examined and how do you check a baby’s eyes?
I am going to answer the first question today, why should I have my baby’s eyes examined?
The first year of a baby’s life is one of the most critical stages of visual development. 1 out of 10 children is at risk from undiagnosed vision problems. Early detection and treatment can prevent many of the complications vision and eye health problems cause. Some of the problems detected during infant eye exams include lazy eye (amblyopia), muscle imbalance and ocular disease.
Pediatric well baby checks include many tests, but they do not include refractive measurements for unusual or unequal amounts of astigmatism, nearsightedness or farsightedness. These conditions are risks for amblyopia that develops in an otherwise healthy eye. The effected eye is not used properly because the vision is too blurry. Uncorrected blur in an infant’s developing eye can cause the brain to favor the better seeing eye, suppressing vision in the other eye which prevents the vision from developing and causes impairment. This visual impairment can be prevented if detected early enough.
A routine well baby check does not include a dilated pupil examination either. By viewing more of the retina, a better ocular health exam can be performed.
And the best reason to have your baby’s eyes examined is that it is free. Many optometrists, including myself think that infant eye examinations are so important we have signed on to the American Optometric Association’s InfantSEE program. We offer a one-time comprehensive eye assessment to infants in their first year of life. If you have a grandchild, niece, nephew or friend that lives in another area, you can find an InfantSEE provider on the website infantSEE.org.
To give your child a head start to a successful school year, educate yourself on the relationship of healthy eyesight and classroom performance.
Since 80% of a child’s learning is visual, a child’s ability to clearly see the blackboard and words on the page is critical. Many children do not know they have a problem because they think how they see is how everyone else sees. Unfortunately, some students who are labeled as having a learning disability or behavioral problems may simply have a vision impairment.
One in four school-age children have some form of vision problem. A child should not need to start failing in school before we realize there is a problem. Put “eye examination” on your back to school list.
