Myopia is also known as “nearsightedness”, in other words, near objects are clearer than objects far away. Myopia frequently causes issues with driving, blackboard viewing, and in school age children can be an underlying cause as to poor school performance. Myopia is fully correctable with glasses.
Hyperopia is also known as “farsightedness”, in other words far objects are more clear than objects are up close. Depending on the amount of hyperopia, it may be age appropriate and normal, or it could cause headaches and eye strain. If the amount of hyperopia is unequal and different between the two eyes, eye turns and lazy eye may develop. It is important that children be examined early to rule out any abnormal findings. Hyoperopia is correctable with glasses.
Astigmatism is a “warping,” or a misshaping of the cornea. The majority of people have a certain degree of astigmatism since our eyes are not perfect spheres. When astigmatism becomes moderate to severe, objects are seen as blurred and distorted. Astigmatism will affect vision both in the distance and up close, but can be correctable with glasses.
Most people refer to Amblyopia as “lazy eye”. This is a condition when one eye does not perform as well visually as the other eye, even with spectacle correction. This makes it very hard to detect since most people will begin to depend on their “good eye” and perhaps not notice blur from the amblyopic eye. If amblyopia occurs in both eyes at the same time, it is more probable the child will complain of reduced vision, but may still go undetected. Amblyopia develops in childhood between the ages of birth- 9 years old. In order to develop normal vision and depth perception, a young child must “learn” to see clearly. If an exam is never performed or glasses never obtained, the child will reach an age where we can no longer reverse the poor vision so it is important to have children screened early with a comprehensive eye exam by an eye care professional. Amblyopia can be treated with prescription eyeglasses, or patching. Early intervention yields better results.
Strabismus is also known as “crossed eyes” or “misaligned eyes” In general, children usually have strabismus because of an uncorrected amount of hyperopia which is not age appropriate. Esotropia (eyes turning inward) and exotropia (eyes turning outward) are the two most common presentations. Children with strabismus may not complain of vision problems because the brain learns to suppress information from the turned eye. Effectively, the brain “turns the eye off” and may not develop correctly. Children with strabismus may also develop amblyopia in the turned eye. All children with eye turns should be seen and evaluated to rule out any underlying disease.
Adults may have strabismus as well. Sometimes it is carried over from childhood, or it may be new onset. ALL new onset eye turns or double vision should be evaluated by an eye care professional to screen for disease.