In the UK, the average adult now spends over 10 hours a day looking at screens — computers, phones, tablets, and televisions combined. While screens do not cause permanent damage to healthy adult eyes, prolonged use is strongly linked to digital eye strain (also known as computer vision syndrome), which causes symptoms such as tired eyes, dryness, headaches, blurred vision, and neck or shoulder pain. Understanding the mechanisms and practical solutions makes a real difference.
The primary cause of screen-related eye discomfort is reduced blinking. Studies show that our blink rate drops by up to 60% during concentrated screen use, and the blinks that do occur are often incomplete — the eyelids do not fully close. This leads to faster tear film evaporation and the gritty, dry, tired sensation that millions of screen workers experience daily. The 20-20-20 rule is the simplest evidence-based countermeasure: every 20 minutes, look at something 20 feet away for 20 seconds, and consciously blink several times.
Blue light from screens has received considerable attention in recent years, but the evidence should be kept in perspective. The amount of blue light emitted by screens is a fraction of what the sun produces, and no robust clinical evidence shows that blue light from screens causes damage to the retina. The College of Optometrists and the American Academy of Ophthalmology both state that blue light blocking lenses are not necessary for preventing eye disease. However, reducing blue light exposure in the evening — using your device's built-in night mode — may help with sleep quality, as blue light can suppress melatonin production.
For children, the relationship between screen time and eye health has an additional dimension. Emerging research suggests that increased near work and insufficient time outdoors are contributing to the rising prevalence of myopia (short-sightedness) in children. While it is difficult to isolate screen use from other near-work activities, encouraging children to spend at least two hours outdoors every day is one of the strongest evidence-based recommendations for reducing myopia risk.
Practical steps for comfortable screen use include: positioning your monitor at arm's length with the top of the screen at or slightly below eye level; adjusting screen brightness to match the ambient lighting; using a desk lamp to illuminate documents rather than relying on screen brightness alone; ensuring your glasses prescription is up to date (a small uncorrected error causes disproportionate strain during screen work); and considering occupational lenses designed for intermediate and near distances if you spend your working day at a computer. If symptoms of digital eye strain persist despite these adjustments, book an eye test — your optometrist can check for underlying dry eye or refractive issues that may need treatment.