Strabismus

[3] If present during a large part of childhood, it may result in amblyopia, or lazy eyes, and loss of depth perception.

[3] Strabismus can occur due to muscle dysfunction (e.g., myasthenia gravis[4][5]), farsightedness, problems in the brain, trauma, or infections.

[3] Risk factors include premature birth, cerebral palsy, and a family history of the condition.

[3] Diagnosis may be made by observing the light reflecting from the person's eyes and finding that it is not centered on the pupil.

This deficit may not be noticeable in someone who has had strabismus since birth or early childhood, as they have likely learned to judge depth and distances using monocular cues.

A socioeconomic consideration exists as well in the context of decisions regarding strabismus treatment,[10][11][12] including efforts to re-establish binocular vision and the possibility of stereopsis recovery.

This is due not only to an altered aesthetic appearance but also because of the inherent symbolic nature of the eye and gaze and the vitally important role they play in an individual's life as social components.

[14] Notably, strabismus interferes with normal eye contact, often causing embarrassment, anger, and feelings of awkwardness, thereby affecting social communication in a fundamental way, with a possible negative effect on self esteem.

Researchers have theorized that esotropia (an inward turn) was not found to be linked to a higher propensity for mental illness due to the age range of the participants, as well as the shorter follow-up time period; esotropic children were monitored to a mean age of 15.8 years, compared with 20.3 years for the exotropic group.

[19] Studies in which subjects were shown images of strabismic and non-strabismic persons showed a strong negative bias towards those visibly displaying the condition, clearly demonstrating the potential for future socioeconomic implications with regard to employability, as well as other psychosocial effects related to an individual's overall happiness.

[22] Successful surgical correction of strabismus, for adult as well as children, has been shown to have a significantly positive effect on psychological well-being.

The authors of the study suggested that individuals with strabismus may benefit from psychosocial support such as interpersonal skills training.

An impairment of cranial nerve III causes the associated eye to deviate down and out and may or may not affect the size of the pupil.

A manifest deviation, or heterotropia (which may be eso-, exo-, hyper-, hypo-, cyclotropia or a combination of these), is present while the person views a target binocularly, with no occlusion of either eye.

A latent deviation, or heterophoria (eso-, exo-, hyper-, hypo-, cyclophoria or a combination of these), is only present after binocular vision has been interrupted, typically by covering one eye.

This type of person can typically maintain fusion despite the misalignment that occurs when the positioning system is relaxed.

Intermittent strabismus is a combination of both of these types, where the person can achieve fusion, but occasionally or frequently falters to the point of a manifest deviation.

[41][page needed] Unilateral strabismus has been observed to result from a severe or traumatic injury to the affected eye.

Finally, the prefix cyclo- refers to torsional strabismus, which occurs when the eyes rotate around the anterior–posterior axis to become misaligned and is quite rare.

A person with a mild exophoria can maintain fusion during normal circumstances, but when the system is disrupted, the relaxed posture of the eyes is slightly divergent.

[44] Incomitant strabismus of the eso- or exo-type are classified as "alphabet patterns": they are denoted as A- or V- or more rarely λ-, Y- or X-pattern depending on the extent of convergence or divergence when the gaze moves upward or downward.

[45] Types of incomitant strabismus include: Duane syndrome, horizontal gaze palsy, and congenital fibrosis of the extraocular muscles.

It generally occurs in infants and toddlers whose bridge of the nose is wide and flat, causing the appearance of esotropia due to less sclera being visible nasally.

Retinoblastoma may also result in abnormal light reflection from the eye.Strabismus is usually treated with a combination of eyeglasses, vision therapy, and surgery, depending on the underlying reason for the misalignment.

[48] Early treatment of strabismus when the person is a baby may reduce the chance of developing amblyopia and depth perception problems.

However, a review of randomized controlled trials concluded that the use of corrective glasses to prevent strabismus is not supported by existing research.

[52] An alternative to the classical procedure is minimally invasive strabismus surgery (MISS) that uses smaller incisions than usual.

[58] When strabismus is congenital or develops in infancy, it can cause amblyopia, in which the brain ignores input from the deviated eye.

Research suggests this is a behavioral compensation for developmental abnormalities in the routing of nerves in the optic chiasm.

Fayum mummy portrait , c. 150–200 AD
Chelsea goalkeeper Hannah Hampton has strabismus.
A child with accommodative esotropia affecting the right eye. The left eye points forwards while the right eye points inward towards the nose.
A child with accommodative esotropia affecting the right eye
Strabismus correction surgery