The Eye Practice

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 or CLICK HERE for an APPOINTMENT.

Eye Strain (or Asthenopia) affects at least 70% of the population.  A recent study completed by Bausch & Lomb in December 2009 revealed through a random survey done in the USA , Europe and Asia that Eye Strain (or Asthenopia) was experienced by most people.

Approximately 20% of the people that reported eye strain described it in the severe category. 

With such a significant incidence of Eye Strain, what can be done to treat it or suppress it?

There are a few options but before considering treatments it is important to workout what is the possible cause of the perceived Eye Strain.  Sometimes there are a combination of factors that contribute and multiple treatments are required.

       

Classifying different types of Eye Strain in laypersons language can be challenging, but let us give it a try:

1. Uncorrected Refractive error is very common - this includes Hyperopia, Myopia, or Astigmatism.  Refractive error means that the eye in it's relaxed state is not focusing properly.  More detail can be found about these conditions by clicking on the highlighted words above.
2. Eye Muscle Imbalance - this condition is medically called Strabismus.  It is quite a complex area
   but a simple explanation can be found by clicking on the highlighted word above.
3. Overuse syndrome - like any muscle of the body, overusing the eye muscles can cause Eye Strain, which possibly will occur without any sign of focusing problems like refractive error or muscle imbalances like Strabismus.  Just like repetitive strain injuries (RSI) can occur, so can Eye Strain just from reading documents, looking at computer screens, smart phones or playing computer games.

Before any complicated treatment is begun for Eye Strain, every patient needs a thorough comprehensive eye exam that measures for refractive error, eye muscle imbalances and very importantly looks for any underlying eye disease.

If no eye disease is present then correcting one problem at a time is the best approach.  Refractive error is quite common and very simple to fix by either glasses or contact lenses.  Assuming there is a clinical relevant refractive error, it is wise to dispense the glasses or contact lenses and allow the patient to re-challenge their eyes and vision in the same environment that they experienced the original eye strain symptoms.

By prescribing glasses or contact lenses we need to be clear about two common myths:

1. By not wearing glasses or contact lenses when there is clinically significant refractive error only means that eye strain symptoms will persist.  It does not mean that your eyes will strengthen because you do not use the glasses or contact lenses. Nor does it mean that your eyes will weaken because you are using them.
2. Some people that are prescribed glasses think that by straining their eyes that somehow this will make them worse - this also is not true. It just means that the eye strain will be relieved and they will feel better and be more productive.

What is true is that over time, eye muscles tend to get weaker like other parts of our body. I think we can all relate to the fact that a physically fit 20 year old will always be stronger and faster than the same individual that has done their best to be physical fit at 50.

In our next Eye Strain post we will discuss other treatment options, which will include those for eye muscle imbalances and just simple repetitive strain relief tactics.