Digitalized Eyes

for the 21st Century

Technology is amazing. It connects us with family and friends and makes our lives easier in so many ways. But with all the benefits that technology brings, it can also have negative effects. Computer vision syndrome, also called digital eye strain, describes a group of vision-related problems, such as headaches and fatigue, that result from prolonged computer use.

What is

computer vision syndrome?

According to the American Academy of Ophthalmology, computer vision syndrome (CVS) is caused by focusing on small characters on the screen for hours, and by the fact that we blink less frequently when reading from a screen. In most cases, symptoms of CVS occur because the visual demands of the task exceed the visual abilities of the individual to comfortably perform them. Many of the visual symptoms experienced by users are only temporary and will decline after taking a break from computer screens and digital devices.

What are the main symptoms of CVS?

Symptoms of CVS can include the following:

Eye discomfort includes dryness, itching and watery eyes

Eyestrain or headache

Blurred vision


Why does CVS occur?

When our eyes are fixed at a certain focal length for a long time, the ability of the eyes to adjust weakens and eyestrain occurs.

Ciliary muscle strain

Did you know that reading text on a computer screen is harder on the eyes than reading printed text? That is why working on a computer can be more harmful to your vision than reading a book. CVS occurs when people spend hours a day on their screens and digital devices. The frequent change of focus as your eyes move between the screen and documents causes ciliary muscle strain, and you may experience blurred vision as a result.

Reduced blinking

Humans normally blink about 12 times in one minute. However, we may only blink about six times a minute when using computers and other digital screen devices. There is a layer of tear film covering the cornea and it has a number of important functions. It helps lubricate the surface of the eye, provides the cornea with the nutrients and oxygen necessary for its metabolism, and also helps to prevent the growth of microcysts on the cornea. Blinking is the eye’s way of getting the moisture it needs on its surface. Every time you blink, the tear film spreads secretions across the surface of the eyes to keep them from drying out.

Source: Websites of Department of Health – Student Health Service, Project Concern Hong Kong, The Hong Kong Ophthalmological Society, HK01

You may be like