Question

When I go outside I have noticed that I squint in one eye. I have always been nearsighted and have one eye that is considered lazy, but that was corrected with eyeglasses. Lately I had to get bifocals. I had some trouble last year with dizziness. Could this be related to my squint?

Answer

A squint of one eye in bright light is most commonly due to an exo- (outward) deviation of the eye(s). Exotropia is a type of strabismus characterized by outward turning of the eye or eyes, which is present most of the time. The degree of deviation is usually greater when focusing on distant objects, because focusing on near objects normally results in convergence (inturning) of the eyes. Persons and especially children with exotropia may tend to squint in bright sunlight, unlike children with other types of strabismus. Such people may sometimes benefit from prescription glasses or prisms; however, in most cases, strabismus surgery is required to correct the misalignment. Many ophthalmologists prefer to operate on the outside muscles (i.e. those on the ear side) first, using a weakening procedure (lateral rectus muscle recession). However, the inside muscles (those nearest the nose) may also be treated, using a muscle strengthening procedure (medial rectus muscle resection).

Exophoria is an outward deviation that is latent - in other words, it isn't present all the time. It is quite normal to have a small amount of exophoria. However, the degree is generally so small that many people never find out that they have this. I, personally, squint in one eye in bright light, and have done so since childhood. Despite numerous eye exams by many of my colleagues and even strabismus (eye muscle misalignment) experts they have never been able to measure any exo-deviation.

Your history of having a lazy eye points towards your still possibly having a muscle misalignment problem. Most of those who undergo surgery for these problems never get completely cured, and often they can deteriorate again in later life, or be overcorrected in the opposite direction.

I can't relate your dizziness to your eye complaints easily. However, certain infections can affect your equilibrium and cause problems with one of the nerves that run to your eye muscles. This problem is not very common. You should check with your ophthalmologist.

Links

• Optometrist's Network - Strabismus