Eye Strain symptoms require careful evaluation before any treatment plan is instigated. We have made a big deal about excessive computer work and reading as a primary source of Eye Strain (also known as Asthenopia). Even though this is true and in some cases there is no underlying eye problem that can measured. Eye Strain often occurs even though the patient has a perfect eye examination. It is just overuse of the eyes similar to repetitive strain injuries of limbs. In fact there is a condition called ocular tendonitis, which not well documented in the medical literature, which also is a form of eye strain – this will be discussed in further detail in the future.
Even though these days Eye Strain is on the increase due to overuse of the eyes doing computer work and reading, Eye Strain still exists in the traditional form caused by eye muscles and a focusing system that is not co-ordinating properly.
Trying to discuss this topic in one post would be impossible, but what we will try and do is introduce some basic concepts and then expand on these concepts in later posts, while also discussing treatment strategies.
Eye muscle imbalances, if problems are perceived by the patient, are usually fatigue related. The part of the brain that processes vision is called the visual cortex. If the eyes are misaligned significantly, double vision will occur. The brain does its best to not allow this to happen, as it is disorientating. The brain therefore will push the eye muscles to force the eyes into a corresponding position to eliminate double vision. This in turn causes eye muscle fatigue and eye strain (or asthenopia).
A sudden change in eye muscle balance that causes double vision occasionally can be a serious issue. Typically this will occur in an adult and even though rare, can be a sign of a stroke, aneurysm or a tumour compressing one or more of the eye muscle nerves. Luckily this is not common, but sudden double vision always needs to be investigated in case it is something more serious.
Eye muscle imbalances in babies or children can sometimes lead to the eyes being “crossed” and causing one of the eyes (usually the less dominant eye) to become “lazy”. “Crossed” eyes is called strabismus and “lazy” eye is called amblyopia. This is treated with a combination of glasses, eye exercises and occasionally patching of the dominant eye. If this does not provide a satisfactory result then straightening eye muscle surgery can be considered.
If the eyes do not “cross” but the eyes are under strain to continue to see without double vision then there are various categories of imbalances. The following list is not complete but definitely covers the majority of eye muscles imbalances:
- Convergence Insufficiency – this is very common and easily treatable with eye exercises.
- Convergence Excess – this is also common but typically responds better to reading glasses.
The above discussion relates to eye muscle imbalances that are horizontal in nature (across). If only life was that simple. There are also categories of eye muscle imbalances that are vertical (up and down). Then there can be a combination of horizontal and vertical imbalances.
So there we go, we have just skimmed over a huge topic. We will return with more information about Eye Strain and Eye Muscle Imbalances in the future.
In the mean time if you are experiencing Eye Strain that is getting you down we are only a phone or click away. Phone 9290 1899.