Strabismus may occur in adults due to a stroke, diabetes, a tumour, thyroid dysfunction or an injury. It may also be a recurrence of a childhood strabismus that has been surgically corrected.
As we age, just like with most muscles in our body, the muscles controlling our eye movement become lax and any previous or underlying strabismus may worsen or become apparent.
Adult patients with sudden onset strabismus will often experience diplopia (double vision). This may be horizontal (where the two images appear side by side), vertical (where the images appear one above the other) or a mixture of the two (diagonal diplopia).
Diplopia occurs when both eyes are open and resolves when one eye is closed. Monocular diplopia persists when one eye is closed, an usually results from the need for glasses not from muscle imbalance.
Adult strabismus resulting from disease can resolve over time. It is a slow process and can take anywhere from several weeks to several months or even years. Once the process is complete, any residual strabismus may be corrected with surgery, providing that this will not compromise binocular vision.