By Hira Nath Dahal Bachelor of Optometry
A headache has been a universal thing these days. There are many causes of a headache: systemic as well as the ocular cause. Because of the greater demand of near work these days where eye is involved, any ocular cause should be ruled out.
Detailed eye examination including prompt refraction along with binocular vision assessment is essential for detecting any ocular case. Appropriate correction of refractive error especially astigmatism and hyperopia with spectacles may decrease the symptoms in patient.
Because of greater demand of near work these days where eye is involved, any ocular cause should be ruled out. Our eyes have a tendency to change its power while seeing the near distance from far distance. This is called focusing power of eye or accommodation. Because of greater demand of near work these days where eye is involved, our eyes have to focus for prolonged period of time i.e. it has to exert continuous effort. This will lead to condition known as accommodative spasm (condition where are makes very high effort itself when it don’t have to focus) that generally occurs in young patients and causes eye pain, decreased vision for distance. Also, there could be other near vision problems that is called non strabismic binocular visual problems that will create a difficulty for the eye to do continuous near activities. For performing the near activities efficiently, our both eyes should point at the same point known as eye teaming and should have same focus (eye focusing). Disruption in this mechanism will lead to headache, most of which will be in temporal part of our head. This will cause the sufferer to correct or overcompensate for this misalignment creating strain on the muscles in the eye because he or she is constantly trying to re-align the eyes to eliminate blurriness and double vision.
So, if anyone have eye teaming and eye focusing problems, a standard eye exam might not be able to catch it.
Sometimes the patient themselves complains of different problems. These include dizziness, headache, light sensitivity. Many such cases have been misdiagnosed with having migraine disorder, sinus headache and vertigo. Having misaligned eyes can also create difficulty in learning and reading. Specifically, these kinds of problems can make feel tired while reading, cause words to blend together as we are reading, make it hard to read to concentrate and make us skip the lines or lose the place while reading. Often patient report that words move or swim on the page. These very small misalignments are missed on routine eye examination.
In addition to headache, patient might also experience double vision, overlapping or shadowed vision. It can also present as extreme light sensitivity caused by seeing an amplified glare coming from surfaces.
Also, if you have always been clumsy or un-coordinated or have poor eye hand co-ordination, difficulty with sports which require catching or hitting a ball, one may be suffering from eye teaming and eye focusing problems. Besides blurred vision, shadowed vision or layered vision, one also finds covering or closing one eye to make visual tasks easier.
Other problems are difficulty concentrating, having a hard time of meeting someone else’s eyes.
Specifically, to go, we will discuss detailed types and problems these disorders cause:
Convergence Insufficiency (Eye teaming disorders)
It is a common binocular disorder in which the eye doesn’t work cohesively at close distances and drift apart or cross during reading and other close activities. The worse thing about convergence insufficiency is that a person can pass typical 20/20 eye chart test and still have it.
Many people that have convergence insufficiency won’t complain of symptoms because the brain will ignore the input of one eye to avoid the double vision. This vision suppression causes the loss of binocular vision and depth perception. This has a negative impact on coordination, sports, distance judgment, eye contact and motion sickness.
The next type of disorders will be discussed in an upcoming blog.
If you feel like you are having above-explained problems, please come for a diagnosis at Drishti Eye Care Center, Kalanki, Kathmandu where we have Binocular vision clinic. We recommend your child for an eye exam before they are 6 years old. A simple school exam isn’t enough to diagnose binocular vision disorders, a comprehensive eye exam is necessary.