Squint (Strabismus)

Strabismus, also known as crossed eyes, is a state in which your eyes do not look in the same direction. They are lined up in different directions, each eye focusing on a different object. 

It is most commonly found in children. There are six muscles in the eyes which are responsible for controlling the eye movement, and if any of these muscles is affected then it may result in abnormal eye movement. If the alignment of the eye is disturbed, it results in strabismus. It is caused due to inability of eye muscles to control the movements. 

Crossed eyes may develop due to abnormality in nerves associated with eye movement. Strabismus that was not treated in childhood may result in its recurrence in adulthood. Symptoms include seeing two images of the same object when there is only one image (double vision). It also includes visual confusion and turning of face or tilting of head to compensate for double vision. To evaluate strabismus, MRI or blood tests are necessary. Sudden development of strabismus results from other conditions like stroke, injury to the brain, and Graves' disease.

Causes- are mostly hereditary.

Other disorders that may cause strabismus include- 

1. Cerebral palsy
2. Brain injury
3. Retinopathy
4. Botulism
5. Guillain barre syndrome
6. Hemangioma

1. Being underweight at the time of birth
2. Smoking at the time of pregnancy
3. Familial history
4. Cicatricial retinopathy 
5. Farsightedness
6. The difference in refractive error between both eyes
7. Prematurity 
8. Graves' disease 

1. Reduced Vision
2. Blurred Vision 
3. The strain on the eyes
4. Headache
5. Changes in perception of height or depth of places 
6. In the presence of bright light, difficulty in opening eyes
7. Leaning of the head towards one side

1. Patient history related to family, medications, and other conditions.
2. Visual acuity studying alphabets from a chart
3. Refraction examines the eyes with a sequence of lenses to calculate how they concentrate on the light.
4. Symmetry and focus tests
5. After dilation (widening) of the pupils, internal eye structures are examined.
6. Examination of eyes.
7. In order to observe divergence of eyes, cover-uncover tests are performed.
8. In order to diagnose other conditions related to strabismus, a neurological examination is performed.

It includes the following:

1. Eye exercises like pencil pushups, Brock strings, and barrel cards.
   1. Pencil push-ups are easy vision exercises in order to get both eyes focused on the same point. In order to perform this exercise, you need to hold a pencil at arm's length far from you. Concentrate on the object or letter on the side and move the pencil towards your nose. Concentrate as long as you can and halt the exercise in case of blurred vision.
   2. Brock strings use a string of 152 centimetres with dissimilar beads and tie one end of the string to an immobilised point. Align the beads to equal distance and hold the other end of the string to the nose. Brock string exercise helps to focus on a particular object at a specific time.
2. Eyeglasses or contact lenses.
3. Using eye patches on the eye to treat lazy eyes.
4. Medications include the usage of botulinum toxins to weaken the eye muscle.
5. Atropine drops are also used in place of eye patches in kids.

1. Help eliminate symptoms like fatigue or eye strain and double vision
2. Restores the usual relationships between both the eyes as well as with other facial structures. 
3. Improves appearance
4. Helps improve side vision in some cases
5. Sometimes help to improve perception of depth

1. Permanent vision loss if not treated in time.
2. Lazy eye or amblyopia-  It is a decrease in eyesight due to abnormal visual development.