An Overview of Asthenopia (Eye Strain)

Asthenopia (eye strain) is a feeling that your eyes are tired, sore, or achy. You can feel this way after reading or looking at a computer or phone screen for a long time. This sensation develops due to prolonged use of the muscles that control your eye movements and your pupils (the dark circles of your eyes).

You may also be more prone to eye strain if you have dry eyes or if you have a vision problem but don't use corrective lenses. Most of the time, resting your eyes and making sure your eyes are in good health should alleviate eye strain.

When it is a problem for you, however, you can try a number of practical solutions, such as adjusting the glare on your computer screen or changing light levels in the room.

Anyone can experience eye strain. It is a fairly common problem in children and adults of all ages. You might feel the effects while you are still reading or looking at a screen, but sometimes you may not notice them until you take a break from what you are doing.

The effects of eye strain usually last for a few minutes, but at times they can persist for several hours. If you frequently experience eye strain without taking breaks, you can start to develop the symptoms earlier and more often—instead of beginning after hours of using your eyes, the symptoms may start right away

Eye strain produces a number of symptoms, including:

• Eye pain
• Dry eyes
• Itching or burning eyes
• Squinting
• Headaches, especially around your eyes and forehead
• Blurred or doubled vision
• Poor concentration
• Photophobia (light sensitivity)

You may also experience neck pain and shoulder pain when you have eye strain. This is because the physical positions that lead to eye strain can also cause muscle strain in your body.

Eye strain occurs after long periods of intensely focusing your eyes. Activities such as reading, driving, or working on a tiny craft or project can lead to eye strain.

Frequent use of smartphones and other handheld electronic devices may lead to asthenopia symptoms. Surfing the Internet or reading text messages and emails can be extremely taxing to the visual system, as the eyes must strain to read the small fonts and the blue light can be bothersome.

People who are especially prone to digital eye strain include:

• Students who spend hours reading or working on a computer
• People who work at a computer all day
• People in professions that involve daily intensive reading, including radiologists, lawyers, and accountants

It isn't just working that leads to eye strain, though. Playing video games can cause it, too, both because you're intensely focusing your eyes and rapidly moving them back and forth.

Anyone can get eye strain, but vision deficits (farsightedness, nearsightedness, presbyopia, etc.) can increase the risk of eye strain. Some eye conditions can make the effects of eye strain more of a problem.

Vision deficits make it harder for you to focus your eyes, so your eye muscles will literally strain as you concentrate on a small font or print. When one eye is worse than the other, the effort it takes to focus both of them can cause eye strain, as well.

A number of muscles help you focus your eyes. Like any muscles, they can become exhausted and lead to eye fatigue.

Ciliary muscles move your pupils—constricting them (making them smaller) for close vision and dilating them (making them larger) for far away vision.

Moving your eyes back and forth rapidly, such as when playing a video game, exhausts your extraocular muscles that move your eyes from side to side and up and down.

If your symptoms are obviously caused by focusing on screens, small print, or other small objects, and then is relieved with a few minutes of rest, then you probably have eye strain. If it's common, you might have a vision deficit and your vision can improve with correction.

If you have other symptoms, such as nausea or severe eye pain, your doctor may need to run some diagnostic tests to check for other problems.

An eye exam includes vision testing and involves a detailed examination of the structure of your eyes using non-invasive devices, such as an ophthalmoscope.

Several conditions can produce symptoms similar to those of eye strain, including:

• Migraines: If you have eye pain, fatigue, headaches, photophobia (light sensitivity), and irritability, you could have migraines. While migraines can be triggered by eye strain, they tend to last longer than the effects of eye strain and don't improve with eye rest.
• Tension headaches: These headaches feel like pressure on your forehead and around the back of your head and they can lead to pain behind your eyes. Tension headaches can be accompanied by eye strain. These headaches typically improve with over-the-counter pain relievers like Advil (ibuprofen) and Tylenol (acetaminophen), but eye strain usually does not.
• Fatigue: Exhaustion, sleepiness, and feeling worn out can make you want to just close your eyes. Usually, these symptoms are relieved by rest and sleeping, while eye strain is relieved by resting your eyes.
• Viral conjunctivitis: Also referred to as pink eye, this common condition is highly contagious. With viral conjunctivitis, the white part of your eyes appear pink, you develop crustiness around your eyes and eyelids, and your eyes feel very itchy and possibly painful.

No medication or procedure can relieve eye strain, but you can learn useful strategies for managing it, such as:

• Resting your eyes: When you feel eye strain coming on, or even if it is at its worst, just close your eyes for a few seconds. Additionally, give your eyes a break by looking at something that isn't so small or detailed.
• Lighting changes: Use proper lighting when you are reading or working. Even if you feel comfortable in dim light, you could suffer from eye strain later on.
• Computer and phone screens: Set your screens just bright enough so there's a comfortable amount of contrast for reading.
• Sit back farther: You should be an arm's length away from your computer screen.
• Font sizes: Adjust the font size on your phone or computer. A font that is too small can be hard to see, while large font fills up too much space on the screen, making it cumbersome to read large documents. Use a clear font without too many hard-to-read squiggles whenever possible.
• Taking breaks: If you perform tasks that require prolonged reading or looking at tiny objects, look away every 20 minutes or so. You can close your eyes or look at something far away to give your eye muscles a rest. You might worry that it'll slow your productivity, but it will likely increase the amount of time your eyes can stay on the task.
• Correction for vision problems: If eye strain is a major problem for you, it could be due to a vision problem. Make an appointment to have your eyes checked.

Eye strain is fairly common, but you may benefit from adopting habits that give your eyes a rest. Remember that your vision can change over the years, so regular eye exams can identify and correct vision problems and be another way to relieve eye strain.