Definition

Eye strain (asthenopia) is a subjective condition arising from prolonged use of the eyes. A study in the United States involving 10,000 adults found that 65% of subjects reported symptoms of eye strain. 

This condition is especially prevalent among individuals who use two electronic devices simultaneously. Another study with 1,462 students reported that approximately 71.2% experienced at least one symptom of eye strain, indicating its common occurrence in society.

Causes

Eye strain has multiple causes. The primary cause is strain due to accommodation, where the eye adjusts to clearly see objects at varying distances. Normally, the lens shape and pupil size adjust to focus light on the retina accurately. However, when there is no correction from glasses or contact lenses, or if the corrective lenses are too concave, the muscles regulating the pupil and lens shape become fatigued. This increased effort to focus leads to eye strain.

Lighting errors also contribute to eye strain. Bright light causes pupils to contract, while dim light causes them to dilate. Inconsistent lighting, whether too bright or too dark, tires the muscles controlling the pupils. Additionally, prolonged focus on a single object or direction, such as reading, driving, or using gadgets, strains the eye muscles due to continuous maintenance of one position. Eye strain can occur more easily if there is an imbalance in the eye muscles.

A less recognized cause is continuous exposure to dry air from fans or air conditioners.

Specific to gadget use, eye strain is referred to as computer vision syndrome (CVS). Prolonged use of computers or laptops leads to reduced blinking, essential for keeping the eyes moist. Furthermore, the close distance between the gadget and the eyes, along with poor lighting settings, such as low contrast between text and background or reflective screens, exacerbates eye fatigue.

Risk Factor

Risk factors for eye strain include jobs requiring prolonged focus in one direction, extensive use of computers or laptops, and uncorrected visual abnormalities with no usage of glasses or contact lenses, such as nearsightedness, farsightedness, and astigmatism. Diseases that cause an imbalance in eye muscle strength and the inability to maintain proper eyeball positioning when viewing close objects also increase the risk.

Symptoms

Common symptoms of eye strain include pain in and around the eyes, headaches triggered by close object viewing, fatigue, dizziness, nausea, facial muscle twitches, and migraines (one-sided headaches). Other symptoms include dry or watery eyes, tense neck and shoulders, increased sensitivity to light, and concentration difficulty.

Diagnosis

Diagnosing eye strain generally does not require special examinations. However, to identify risk factors, a doctor may perform tests to examine visual acuity, light reflex, eyeball position and movement, and visual field. The doctor may also assess whether corrective glasses are needed to improve vision and alleviate symptoms.

A diagnosis of eye strain is made if no serious eye disease is present.

Management

Eye strain can generally be treated at home. Here are some steps you can take:

• Limit electronic device use: This is especially important for children who might not understand the link between prolonged device use and eye strain.
• Rest your eyes: Follow the 20-20-20 rule: every 20 minutes, look at an object 20 feet (6 meters) away for 20 seconds.
• Adjust screen position: Ensure your screen is directly in front of you at arm's length, with the top of the screen at or slightly below eye level. Using an adjustable chair can help.
• Adjust lighting: Proper lighting can prevent eye strain. Avoid overly bright lights when watching TV and ensure task lighting for reading or close-up work comes from behind you. A table lamp with a shade can direct light properly without straining your eyes.
• Adjust gadget screen light: Set your screen brightness to a comfortable level and ensure the contrast is easy on your eyes. Increase the font size for easier reading.
• Use artificial tear drops: Over-the-counter artificial tear drops can prevent or relieve dry eyes. Avoid drops that reduce eye redness. Use them regularly to maintain eye moisture.
• Improve air quality: Use a humidifier to maintain air moisture and adjust the air conditioner to avoid strong airflow. Avoid smoky environments, and consider quitting smoking if you smoke.
• Choose appropriate vision aids: If prescribed by a doctor, use glasses or contact lenses designed for prolonged gadget use. Specific coatings and types of lenses can control light entering the eye effectively.

If you or your child has eye conditions like strabismus or imbalanced eye muscle strength, a doctor can provide appropriate treatment.

Complications

Eye strain typically does not cause serious complications.

Prevention

Prevent eye strain by limiting electronic device use, following the 20-20-20 rule, and adjusting the position and brightness of your screens and lights.

When to See a Doctor?

If preventive measures and self-treatment do not alleviate eye strain, consult a doctor. If you experience blurred vision, a doctor can determine if you need glasses.

For children under 12 who complain of eye strain, see a doctor promptly to address potential conditions like strabismus or imbalanced eye muscle strength before they lead to vision complications in adulthood.

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