Commonly is referred to as a squint and is medically known as strabismus, derived from the Greek word (strab-is-mos).
The eyes are not aligned with each other eye. The position of one eye may look:-
- Inwards, known as a Convergent Squint or cross-eyed turning towards the nose (see picture);
- Outwards, known as Divergent Squint turning towards the ear (see picture below),
- Upwards- towards the eyebrow.
- Downwards – towards the cheek.
It may be a combination of both, for example inwards AND upwards.
There are 6 extra-ocular muscles in each eye and they have to work together with the other eye as a pair to achieve single vision when staring at something in space.
For example: Looking to the right
What causes a squint?
The reasons squint develops is due to some of the following:
- It is in the family: A child is more likely to have a squint. For example Grandmother (A) has a squint. Her son (B) has a squint and his second daughter (C) has a squint.
- Need for Glasses: The child has to focus more to see clearly that may cause a squint.
- Congential: A child is born with a squint or it is noticed usually within the first 6-months of life.
- Illness or trauma: Nerve damaged by an illness or a trauma may cause a squint.
A squint may affect vision. The brain ignores the image coming from the squinting eye and starts to become lazy otherwise known as amblyopia (am-bly-opia) meaning lazy or poor vision not blind vision.
This test is crucial to assess the presence and type of a squint. It is a simple procedure using a cover to occlude one eye and see the movement of the other eye.
If one of the eye is covered with the black cover (occluder) the other eye will move to view the object/image.