Aarya Eye Care

Digital Eye Strain

What is digital eye strain?

Digital eye strain (DES) is the term used for a variety of eye conditions and vision-related symptoms linked to the prolonged use of digital devices such as mobile phones, tablets and, computers. It is also known as computer vision syndrome (CVS) and visual fatigue (VF).

The following sections will briefly outline the public health implications of DES, what causes DES, its signs and symptoms, and some insights into its management and treatment.

How many people suffer from digital eye strain?

DES is a global problem that affects people of every age group, gender, and nationality.

Digital eye strain in children

Children born into this digital age are raised with digital devices playing an important role in their daily lives. In most cases, they are not sufficiently informed on how to develop healthy relationships with their digital devices in order to keep themselves safe online and their eyes healthy. A study conducted in India on students aged 11 to 17 years found that 1 in 5 students reported symptoms of DES, with more than 40% of those with DES spending 2 to 4 hours on a digital device daily.

What causes digital eye strain?

DES is caused by a number of different factors linked to the excessive use of digital devices . Some of these factors include the length of duration spent in front of a digital device screen, the working distance between digital devices to the eyes, the number of times a digital device is used in a day, and even the number of digital devices being used at the same time. The light intensity in the surrounding working environment is also an important factor that contributes to the development of DES.

Effect of prolonged screen time

Spending 2 or more hours in front of a digital device screen each day has been found to reduce the number of blinks per minute (blink rate). The act of blinking helps to keep the front surface of the eye moist and clears any particles that may be stuck in the eyes. A lower blink rate is found to be linked to dry eye, which is a common symptom of DES. The average person blinks about 15 times each minute, and studies have shown that this number could decrease by 60% to 6 times per minute when a person uses digital devices .

Effect of the number of digital devices being used at the same time

The number of digital devices being used at the same time may also contribute to DES. A study conducted in the US found that nearly 8 in 10 Americans who suffer from DES regularly use 2 or more digital devices at the same time . This is particularly concerning considering that in countries such as Singapore, the average adult owns about 3.3 digital devices .

Effect of working angle and distance

The angle and distance from which a digital device screen is being viewed may lead to symptoms of DES. Desktop computer screens are usually viewed with a horizontal gaze. This will cause the eyes to open wider as compared to viewing a mobile phone or tablet, which is usually viewed with a downward gaze. The wider exposed front surface of the eye may cause evaporation of the tear film, resulting in dry eye, a common symptom of DES .

The distance at which a digital device is being viewed at may also lead to symptoms of DES, especially if the device is held too close to the eyes. When viewing objects that are very near to the eyes, the ciliary muscles (the muscles that change the shape of the lens of the eye to help focus incoming light) will contract. Staring too close to a digital device screen for longer than 2 hours each day may cause the ciliary muscles to contract for an extended period of time, resulting in eye strain, which is also a common symptom of DES .


Effect of the amount of light in the surrounding working environment

When using a digital device in a working environment where the light is too bright, the light from the surrounding environment will compete with the light coming from the digital device screen, making it too harsh for the eyes. The exposure to this harsh light for extended periods may lead to eye strain.

Viewing a digital screen in an environment with not enough light may also cause added strain to the eyes. Under dim light, the pupil (the black circle in the centre part of the eye) increases in size so that sufficient light enters the eye, allowing the person to see better. Spending an extended time working under dim light may cause increased strain to the eyes, resulting in symptoms of DES.

Glare from a digital device screen is also a contributing factor for DES. In 2019, a study conducted in Taiwan found that adults (aged 20-35 years) who were exposed to a glare-free environment demonstrated fewer symptoms of tired eyes and better results when performing eye-related tasks as compared to participants in a high glare environment .

What are the common symptoms of digital eye strain?

According to theAmerican Optometric Association , the common symptoms of DES include:

Blurred vision

Eye strain (Asthenopia)


Dry eyes

Neck and shoulder pain

Other reported symptoms of DES include:

Eye discomfort

Difficulty refocusing the eyes from near to distant objects and from distant to near objects

Irritation of the eye

Sensitivity to bright lights

The symptoms of DES are divided into two categories, those that are linked to the function of the eye that allows it to focus light (accommodation) and those linked to dry eye.

Symptoms linked to the eyes’ focusing ability tend to be the ones that are felt internally, such as headaches, blurred vision, difficulty refocusing the eyes, and eye strain.

Symptoms linked to dry eye tend to be those that affect the external areas of the eye, such as eye dryness, irritation, and discomfort.

If you experience any of these signs and symptoms, schedule an appointment with our consultants to get your eyes checked. It is also important to note that the development of eye conditions may even start before symptoms appear, which makes going for regular and timely eye checks that much more essential.