Strabismus is the medical term for what people commonly call “crossed eyes”, a condition that is both disconcerting for a sufferer and for someone looking into eyes of a person who has the condition.
Also referred to as “lazy eye” or “squint”, strabismus happens when the six muscles that help work the eye into its required orientation, do not function together properly.
Eyes can be affected mildly, but more serious cases can present a significant danger in that over time the weaker, some would say lazier, eye may cease to focus at all. This may be because the brain, confused by the conflicting eye signals eventually chooses not to recognise it, leading to that weaker eye ceasing to contribute at all when both eyes are open. If the better is closed and the “weaker” eye is used the patient with strabismus will see, but not clearly. Peripheral vision in the “strabismic” is usually normal.
In these cases it is essential that some kind of treatment be initiated as early as is practicable.
Who is likely to get a Strabismus?
Children form the major group of those likely to have a strabismus. Many babies are born with a very slight squint which rectifies itself, but to be sure about things it’s recommended that they be examined from three to six months old.
On occasion a child with a flat nose might appear to have a squint, but as he or she grows and an adult type nose forms, it often seems to go away, not really being there in the first place. This is called a pseudostrabismus.
Causes of Strabismus
There are three main areas of cause:
• Genetic factors – family members may show a history
• Acquisition during normal growth to adult and beyond
• As a side effect from some disorder such as a cataract or glaucoma
Symptoms and diagnosis
Although thought of as being easy to see, a strabismus may not always be “on view” – it may be only when a person is tired or in bad health that it’s readily visible.
The single main symptom is that the eyes don’t move together, with one eye maybe turning out or up as the strong eye is focussed on something. Other symptoms brought out in interview are often double vision (as when you temporarily cross your eyes yourself), loss of vision or lack of seeing in depth without the benefits of 3D.
An optometrist will perform a thorough examination as well as a series of eye tests to measure the degree of the strabismus. One test is cleverly designed to make use of the fact that there should be a direct reflection from the eye when a light is shone into it – if a pair of eyes line up in a normal way then they should both reflect to the same spot.
Mature adults are more likely to see double with an acquired strabismus as the eyes haven’t compensated for it. Children often don’t see double as the brain is used to it from the beginning.
Treatment can be simple or surgical
The easiest and very often the simplest and most effective way to cure a strabismus is to get the patient to wear a patch over the STRONGER eye – this then makes the weaker eye do more work and start to align itself. In days gone by children were forced to wear the patch all day every day. Recent studies have shown that wearing a patch over the better eye for 2 – 3 hours a day only at home is just as effective. This has been a very important discovery, as many children were not compliant with eye patching.
Instead of a patch, glasses with an opaque lens over the stronger eye have the same effect and are often more accommodating in terms of lifestyle. This is also outdated ever since the 2 – 3 hour patch studies have been published.
Surgery involves cutting into the skin round the eye to get to the muscles, detaching them and re-attaching them to produce the required alignment. Recovery is within a few days, and is followed by new glasses and often further patching being prescribed.
What can you do to alleviate uneasiness looking at someone with a strabismus?
The problem with a strabismus is that it prevents the normal eye contact between people that forms an important part of communication and body language.
Understanding what a strabismus is and that a sufferer may be feeling lack of self esteem through awkwardness should incline us to empathise and not be embarrassed in any way.