Normally, when thinking about an eye turn or strabismus, the eye turn begins in childhood. These types of strabismus are common and usually do not have a direct cause. However, if an eye turn develops in adulthood, there is usually a direct environmental cause or pathology that causes the eye turn. Potential causes include damage to the eye from an injury, a stroke, or compression from a lesion or tumor. All of these causes can be serious and thus any new eye turn should prompt quick evaluation from an eye doctor.
Types of Eye Turns
An eye turn occurs when one eye is not looking at the same location as the other.
There can be an eye turn in, out, up, or down.
If the eye turn is large enough, it will be noticeable when looking at the person and may cause the individual to have double vision when both eyes are open.
The magnitude of the deviation can be measured and the eye turn can be classified based on the direction of the turn and the magnitude.
Causes of Eye Turns in Adults
If there is an eye turn in an adult, most likely it has been present since childhood. However, if the turn is newly developed, there is likely an underlying cause.
A stroke, or cardiovascular accident, can also damage the nerves that control the eye muscles and lead to an eye turn.
Similarly, a tumor or other compressive lesion in the brain or orbit can cause the nerves that are responsible for the eye muscles to become damaged or weakened and incite an eye turn.
Traumatic Ocular Injury
If an eye experiences an injury, one of the possible outcomes is that the eye begins to turn out or in.
This type of eye turn is usually due to the loss of vision in the damaged eye and the resulting poor vision leads to an eye that is likely to turn out or in.
If there is an injury to the head, the trouble at the nerve can become severely damaged with minimal force and lead to an eye turn.
This type of eye turn is due to the lack of innervation in the superior oblique muscle.
Stroke and Tumors can Cause Strabismis
If there is a stroke in the brain, it can cause a loss of oxygen to the nerves which control eye movements.
These nerves reside in the brain stem and can be impacted by a stroke in the surrounding area.
If one or more of the cranial nerves that control the eye muscles are damaged, an eye turn can develop because one of the eye muscles is no longer functioning as well.
Determination of Cause of Adult Eye Turn
If an eye turn does develop in an adult, an eye examination and possibly additional tests such as MRI or CT scan can help diagnose any problem.