Screen Time and Eye Health

Computer vision syndrome

A common disorder that is attributed to screen time and eye health, is Computer Vision Syndrome. This is a complex syndrome caused by the overstraining of the visual system because of prolonged work at the computer or other digital screen.

The term "computer vision syndrome" was introduced by American ophthalmologists in 1998 because of the combination of changes in the eyeball that occur when using a computer.

According to modern concepts, working at a computer itself is not a source of serious organic pathology. Most of the problems are associated with functional changes in the eyes, neck, back, and shoulders. In the process, there is a constant shift of gaze from the display to the keyboard, which significantly increases the strain on the eyes.

Most often, pathology occurs between the ages of 18 and 45 years in people who constantly work on a computer. In women, computer syndrome develops faster.

Reasons for development

As a result of evolutionary development, the human eye has adapted to perceive objects and texts only in reflected light; it is poorly adapted to the perception of information from computer monitors or tablets. The image on the displays of computer technology is presented in the form of dots and luminous pixels, which is significantly different from the paper text.

On a computer monitor, the lines of letters are less contrasting and have no clear boundaries. All this reduces the accuracy of accommodative focusing and leads to the formation of an accommodation lag. Accommodation is the ability of the lens to change its shape (become either flat or more convex) to accurately focus on objects that are located at different distances from the human eye.

During prolonged work at the computer, the accommodative mechanism of the eyeball is in constant tension, which causes irregularities in the focusing of the eye. As a result, involuntary twitching from the display to the resting point of accommodation occurs.

Twitching from a focus on the screen to a resting point leads to fatigue and overstrain of the apparatus of the eye. In addition, during work, there is a decrease in the frequency of blinking due to the fixation of the gaze on the monitor. All this contributes to the development of computer vision syndrome.

Symptoms and diagnosis

The clinical diagnosis of this syndrome is divided into visual and ocular. Visual symptoms include a decrease in visual acuity, the development of habitually excessive disturbances (a patient may complain about blurred objects when looking from a computer screen into the distance).

The appearance of diplopia, discomfort when reading is possible. Also, with Computer Vision Syndrome, the McCollough effect can be detected (when you look from the computer display to the wall, a colored spot appears).

With the development of eye symptoms, patients complain of pain when moving the eyeballs as well as pain that spreads to the supraorbital and frontal regions. Complications of computer syndrome include the development of dry eye syndrome, mild myopia, and paresis of accommodation.

Diagnosis of computer vision syndrome begins with taking anamnesis. An external examination is then carried out using tonometry and computer perimetry while determining the acuity and nature of vision. Biomicroscopy is performed using a slit lamp and an aspherical lens. An obligatory part of the examination is the study of eye refraction using cycloplegia and measuring the volume of absolute and relative accommodation.

Treatment and prevention

The treatment of computer vision syndrome is only prescribed when eye symptoms appear. With this diagnosis in ophthalmology, various options for moisturizing drops or gels are used to protect the cornea from drying out and reducing discomfort when working at a computer.

Prevention is the most effective way to stop the development of computer vision syndrome. It is necessary to take breaks from working at the computer, preferably every hour (for a working day lasting 8 hours, the breaks in total should be at least 1.5 hours; for a 12-hour shift, 2 hours per work shift) and perform exercises to relax the accommodation of the eye (for 2-3 minutes).

General eye health and work

With regular long-term work with a personal computer, it is advisable to consider several rules to reduce the symptoms of computer vision syndrome, to properly organize the work area. Adequate lighting, a computer with a good display, and correct settings are required. It is better to choose the dimensions of the monitor diagonally from 50 cm and above, with mandatory protection against flickering. Keep the screen free of dust.

The monitor should be installed at about 70 cm from human eyes. For a more comfortable perception, it is better to remove the blue-violet colors from the desktop settings and give preference to the greenish-brown gamut (more comfortable for the visual analyzer). With constant work at the computer, you need to regularly visit an ophthalmologist (preferably once every 6 months).

References:

• Porcar, E.; Pons, A. M.; Lorente, A. (2016). "Visual and ocular effects from the use of flat-panel displays". International Journal of Ophthalmology.
• Izquierdo, Natalio J.; Townsend, William. "Computer Vision Syndrome". Medscape Reference: Drugs, Diseases & Procedures. WebMD LLC. Retrieved 27 December 2021.
• Computer Vision Syndrome Affects Millions. 2016-05-30. Retrieved 23 December 2021.Toomingas, A.; Hagberg, M.; Heiden, M.; Richter, H.; Westergren, K. E.; Tornqvist,
• E. Wigaeus (1 January 2014). "Risk factors, incidence and persistence of symptoms from the eyes among professional computer users". Work (Reading, Mass.).
• Brody, Jane E. (May 31, 2016). "Millions at risk of computer vision syndrome". ET Healthworld. Archived from the original on October 8, 2017. Retrieved December 12, 2021.
• Mainstone, J. C.; Bruce, A. S.; Golding, T. R. (June 1996). "Tear meniscus measurement in the diagnosis of dry eye". Current Eye Research.
• Jones, Paul D.; Holding, Dennis H. (1975-12-20). "Extremely long-term persistence of the McCollough effect". Journal of Experimental Psychology: Human Perception and Performance

Further Reading

• All Eye Content
• How Does the Eye Work?
• Types of Eye Allergy
• Managing and Treating Eye Allergies
• How Does a Cornea Transplant Work?

Written by

Dr. Nicola Williams

I’m currently working as a post-doctoral fellow in the History of Science at the Leeds and Humanities Research Institute (LAHRI), at the University of Leeds. Broadly speaking my research area falls within the remit of the history of biology and history of technology in the twentieth century. More specifically I have specialist knowledge in the areas of electron microscopy and cellular and molecular biology, women in science and visual culture.