We have all experienced the burning eyes and excessive tearing after using a computer screen for a long period of time. In most cases we do not give it much attention and just take time to rest the eyes. However, for some people eyestrain is a daily occurrence and part of an occupational hazard. It is more than just sore eyes and eyestrain can even lead to headaches and affect a person’ ability to concentrate.
What is eyestrain?
Eyestrain is a common eye condition caused by overuse of the eyes. It is usually associated with prolonged hours of gazing at objects at a fixed distance or with very bright or dull lighting. Most cases of eyestrain are not serious but it can affect concentration and sleep and may play a role in triggering conditions like headaches. When eyestrain arises with a condition known as convergence insufficiency then it can affect a person’s ability to work or study.
There has been a greater focus on eyestrain in recent years due to the apparent increase in the condition. This is largely due to the prolonged use of mobile devices, where users are staring at a bright object (illuminated screen) at a fixed distance for long hours. Most of the time eyestrain does not require any specific medical treatment and resolves in a short period of time with rest.
Signs and Symptoms
The main symptoms of eyestrain include:
- Sore eyes, also may be burning or painful
- Redness of the eyes
- Excessive tearing or eye dryness
- Blurred vision, or even double vision in severe cases
Other symptoms that may also be present includes:
- Headaches – front, temporal or a pain behind the eyes
- Light sensitivity
- Heavy eyelids
- Head, neck and upper back muscle spasm
It is important to note that these symptoms are temporary. In the event that the symptoms persist even after resting eyes sufficiently, then it is important to seek medical advice as the symptoms may be due to another condition apart from eyestrain.
Reasons for Eyestrain
Eyestrain arises for two main reasons -muscle fatigue and dryness.
In order to see clearly, light is bent as it passes through the eyeball for a sharp image to be focused on the light-sensitive area at the back of the eye. First light is bent by the cornea, then it is bent by the lens. The shape of the lens can be changed to bend the light to varying degrees in order to focus at objects at different distances.
The muscles controlling the lens become tired when staring at an object at a fixed distance for a long period of time. Muscles that move the eyeballs may also tire. Similarly the muscles that open and close the iris to change pupil size can also become fatigued when faced with long hours of bright light.
Another phenomenon that contributes to eyestrain is the infrequent blinking when concentrating on a specific activity. Blinking allows for the secretion and spreading of lacrimal fluid over the eye surface. The portion of the eyeball in contact with the air begins to dry up and this can further irritate the eyes.
Causes of Eyestrain
The causes of eyestrain are obvious most of the time. However, there are instances where we may be straining our eyes and not even realizing it. Furthermore there are some underlying conditions in which eyestrain is more likely to occur. Sometimes eyestrain occurs as a symptom of fatigue and is often termed tired eyes.
Having dry eyes for any reason increases the risk of eyestrain. This is more of a problem for people who wear contact lenses, work in air conditioned environments or are exposed to windy climates. It can also be linked to conditions like Sjogren’s syndrome, which is an autoimmune disease marked by dryness of the mouth and eyes.
Read more on eye dryness.
Bright light, whether natural such as sunlight or artificial, can also result in eyestrain. The iris muscles have to close the pupils to reduce light entering the eyes due to the intensity. Over short periods of time this may not be a problem but when prolonged, bright light can lead to significant eyestrain.
On the other end, dim light may also contribute to eyestrain especially when staring at a fixed distance like a book in poor lighting. The iris muscles increase the pupil size to allow more light to enter the eyeball. When this has to be maintained for a long period then eyestrain may occur.
Staring or Gazing
Eyestrain is a common consequence of prolonged use of electronic devices with screens and long hours of reading. With regards to devices, a person may stare at a screen which is at a fixed distance for hours. Furthermore these screens may be illuminated thereby causing the eyes to be exposed to bright light. With reading, the eye are focused at a fixed distance for an extended period of time. It can further be exacerbated when reading in dim light.
Eyestrain is more likely to occur in people with underlying eyesight problems. It is especially seen in people who have refractive errors and do not use corrective lenses properly. In these eye problems the light does not bend properly in the eyeball to focus a sharp image, like in nearsightedness (myopia).
Read more on common vision problems.
Treatment of Eyestrain
There is usually no specific treatment that is required for eyestrain. It resolves spontaneously with resting the eyes. Eye drops like artificial tears may help ease some of the symptoms like dry eyes and soreness but this is not a specific treatment for eyestrain. Instead the focus should be on preventing the condition with simple lifestyle measures such as:
- Resting the eyes every 20 minutes for at least 20 seconds.
- Use sunglasses or other protective eye wear when exposed to bright light.
- Reduce the brightness of device screens.
- Ensure appropriate environmental lighting when reading.
Underlying vision problems like nearsightedness (myopia) must be corrected with the appropriate eyewear or LASIK surgery to avoid eyestrain.