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Seeing Into the Future:
Providing Children with the Best Possible Vision Now and Tomorrow
As the new school year approaches, the thoughts of the ECP start to turn to children. This is the perfect time to discuss with parents and schools the importance of vision health in a child’s learning process. Vision is the sense that children rely on the most to discover the world around them. It is reported that approximately 80% of learning occurs through the visual system. There are several basic visual skills that work together to provide the student with the necessary tools to learn properly. These skills include:
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Distance vision
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Near vision
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Binocular fusion
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Focusing clearly for long periods of time and changing focusing distances quickly and easily
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Maintaining awareness of the peripheral environment while viewing things straight ahead
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Accurate eye and hand coordination
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Smooth and accurate eye movement from one point to another
If something occurs early in a child’s life to upset the working of the visual system, learning as well as visual functions can be permanently impaired. Luckily, early detection of problems and subsequent appropriate vision care can correct a situation before it progresses into a lifelong impairment.
Seeing the Signs
Determining if a child is experiencing problems seeing can be difficult, especially in a younger child. The main reason is that children don’t complain about visual problems because they do not know what normal vision is supposed to look like. Children do not realize that they are seeing abnormally. Additionally, a child’s brain adapts quickly to visual discrepancies. In some instances, the brain learns to suppress an image from the weaker or turned eye, resulting in an image that appears correct to the child.
Unfortunately, it is during this critical time, before the age of seven that the visual system is developing. Although a child doesn’t always verbally alert an adult to visual problems, he or she usually displays signs of visual distress. We just need to be alert to their presence.
The first person that a parent or teacher comes to with questions about a child’s visual health is the ECP. Therefore it is important for an ECP to know the signs of visual discomfort and the most common reasons for them. The most frequent signs of vision problems are:
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Headaches- Many headaches are caused by the child straining to hold something into focus. When a child is experiencing a headache, the length of the headache, the trigger for the headache and the method of relief should be noted.
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Winking- If a child closes an eye on a regular basis, it may be a sign of double vision or a blurred image in one eye. This tends to occur frequently when the child is in the bright sunlight. The high illumination can overload their already fragile fusion system.
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Frequent blinking, squeezing the eyes shut, or rubbing the eyes. These are all customary signs of poor focusing.
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Eye misalignment- Any turning of the eye, no matter how slight, can result in double vision (diplopia) and needs to be addressed as quickly as possible.
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Behavioral problems- Visual difficulties can cause a child to become frustrated. Consequently, a child can be mislabeled as unmotivated, hyperactive or a slow learner.
Getting the Exam
The proper recommendation for eye examination is crucial for an ECP. Although an ECP knows to advise an exam to anyone who comes in with signs of visual problems, it is also important to advocate eye health exams at the age of three and again before the child enters school. The first exam at three can help detect vision problems early and ensure that the vision is developing normally. The complete exam before the child begins school can determine if the child’s visual system is equipped to handle the visual demands of school. Prior to school, a child’s visual needs are mostly for distance.
Once school begins, class work requires the child to focus at near on a more consistent basis. Accordingly, visual deficiencies that were undetected before may become more of a hindrance. If no visual correction is needed, an exam every two years is appropriate as long as no signs of visual distress present itself. If correction is needed, then an eye exam should be recommended annually.
Vision screenings are a very important tool for the ECP. It can help detect major problems and it can create a greater amount of eye health awareness to the primary caregivers of many children. However, it is very important that the ECP remind a child’s parent that it does not replace a comprehensive exam. While a screening can determine a child’s visual acuity, it cannot give information about binocular vision, the ability to focus comfortably, or if the child can track print without losing his or her place.
Common Vision Problems and Treatments
Amblyopia
About 5% of children have Amblyopia. Also called “lazy eye”, it occurs when the visual pathway is shut down by the brain due to diplopia or poor vision in one eye causing a distorted image. Since the visual pathways need to develop at an early age, the distortion must be detected and treated early before it is suppressed. If the pathway remains closed until the age of 8, then the visual system is complete and the child will have poor vision for life in the amblyopic eye.
Strabismus
Strabismus is when the eyes do not align properly when under normal conditions. Strabismus is strictly an extra-ocular muscle issue. With this condition, one or both eyes may turn in (eso), out (exo), up (hyper), or down (hypo). If the turning happens on a consistent basis, it is called a tropia. If the eyes align normally most of the time, but have a tendency to turn during times of fatigue or stress, the turning is called a phoria.
Accommodation Problems
Simply put, accommodation is the process of focusing from far to near and vice versa. When children must focus on print for long periods of time, and an accommodation problem is present, the print could become progressively blurry. In addition, the eyes strain trying to keep the print clear and eye fatigue and headaches can occur.
Refractive Errors
Refractive errors are when the light entering the eye doesn’t bend properly and a blurred image results. Hyperopia, or far sightedness, occurs when the light entering the eye focuses behind the retina. The result is blurred images when viewing things up close. Myopia is near sightedness and occurs when the light entering the eye focuses in front of the retina. With this error, far images are blurry. An astigmatism is when the light entering the eye comes into focus at two separate points in the eye. Usually caused by uneven curvature of the cornea, the different foci result in a blurred, wavy image at all distances.
Seeing Clearly
Correcting a child’s vision is crucial for the life-long well being of the child. The most common method of vision correction for children is eyeglasses. When designing lenses for children, safety is crucial.
Polycarbonate:
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Advantages
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Very light weight; 10% lighter than CR-39
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Superior impact resistance – the strongest lens material
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At least 10% thinner than CR-39
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UV protection that blocks approximately 99% of UV up to 380 nm
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Disadvantages
Trivex®
It is imperative that measurements are taken properly when working with polycarbonate and Trivex so that incidences of aberrations are decreased. Both lens materials should be fit with monocular pupillary distances and vertical optical center placement to give the child the best possible vision. In addition, a very close vertex distance is critical.
Conclusion
How a child sees today affects his or her whole life. If the visual process is disrupted at an early age it can lead to a permanent loss of vision if not corrected in a timely manner. It is in this situation that the ECP can have the most impact on a person’s life.
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