Only a few people in the world are born with both eyes having the same optical power. However, the brain often compensates and the condition often goes unnoticed. However, people suffering from anisometropia have a significant difference in the vision between both eyes which interferes with their normal binocular vision.
That means they will see a larger image in one eye and a smaller one in the other resulting in overall blurriness in their vision. Also, they are likely going to get a lazy eye (amblyopia) where one eye has blurry vision for a while and becomes weaker permanently. Anisometropia might present at birth in some cases. An estimate reveals that at least 6% of children between 6 and 18 are definitely going to suffer from this condition.
Types Of Anisometropia
The condition can be categorized into 3.
- a) Simple: Here, one eye will be affected and the other doesn’t have a refractive error (the spectacle prescription). The affected eye will be long-sighted (hyperopic) or short-sighted (myopic).
- b) Compound: Here, both eyes will be short-sighted (myopic) but there will be some significant difference in the refractive errors (spectacle prescriptions). As a result, one eye will see a blurrier image than the other.
- c) Mixed: Here, both eyes will have appreciable refractive errors with one being hyperopic and the other being myopic.
Symptoms Of Anisometropia
The condition presents the following symptoms.
- a) Lazy Eye (Amblyopia): Here, the refractive power found in one of the eyes presents lack of visual stimulation resulting in transmission of insufficient information to the brain through the optic nerve.
- b) Crossed Eye (Strabismus): Here, you will unable to align both eyes. There is lack of coordination in both eyes making it hard to focus on the same point at the same time.
- c) Double Vision (Diplopia): As a result of double vision other symptoms will pop up including headaches, eyestrain, light sensitivity, nausea, tiredness and dizziness.
Causes Of Anisometropia
Anyone with normal vision can suffer from 5% difference in their refractive power of each individual eye. However, anyone with a difference of between 5 and 20% will experience anisometropia, often uneven vision. Some of the causes include defects in the eyes, especially during childbirth, including unevenness in the size of both eyes.
Once the condition is diagnosed, it should be treated immediately. If left untreated, the brain will select the eye with a clearer image and often ignore the other one. It causes a lot of vision dependence on the better eye. With time, the neglected eye becomes weaker progressively. That’s why you need to seek treatment before the condition becomes acute. Be sure to ask your eye doctor about treating the condition via specialty contact lenses.
Anisometropia can be treated in a few ways, often depending on the severity of the condition. For some people, the difference between the two eyes can be managed, especially if the difference is minimal. Other people will require corrective or contact lenses as well as corrective surgery. If you use corrective or contact lenses, you need a different prescription for each eye for the best results.
A person with severe anisometropia is not recommended to wear glasses. Keep in mind that glasses have a magnification effect that causes a huge difference in the image size seen by each individual eye. As a result, wearing glasses with a very severe condition will often prevent exceptional binocular vision.
To learn more about anisometropia, please call us today at (919) 977-7480. Dr. Bassiri and the Fusion Eye Care team look forward to ensuring you get help with your anisometropia.