Computer vision syndrome: A disease of the new age era

Dry eye disease

Prevalence of dry eye disease in visual display terminal worker was found ranging from 9.5% to 87.5% as compared to general population, which has a prevalence of 5–33.3%.^[12] According to Dry Eye Workshop II, the diagnostic methodology for dry eye, the disease includes ocular surface disease index, the TBUT (tear film break up time), osmolarity and ocular surface stain. This standardized criteria points toward higher prevalence of dry eye disease in patients with computer vision syndrome.^[13] Also, reduced blinking rates with the use of computers is frequently associated with dry eye disease.^[14]

Accomodative effects

Numerous studies have found that prolonged near work during the use of digital screen can lead to decrease in accommodation amplitude, acute acquired comitant esotropia leading to diplopia, high lag in accommodation. Dynamic retinoscopy with patient fixating a near target is used to assess lag of accommodation.^[15,16] One hour working time can lead to decreased amplitude of accommodation and retraction of near convergence point.^[1]

Change in intraocular pressure

Eun Ji Lee conducted a study on 158 subjects and reported significant elevation of intraocular pressure at 5 minutes (min) after starting the task and intraocular pressure kept increasing until 30 min viewing period.^[17]

Environmental factors

They also play an important role. Light coming from a source over the device diminishes the contrast and leads to discomfort.^[18] Use of digital screen for more than 4 h per day is a risk factor for dry eye disease and environment of humidity <40% can cause more eye discomfort.^[13] Furthermore, the use of nicotine in a competitive work environment acts as a risk factor.^[1]

Exposure to blue light

Exposure to 400–500 nanometer (blue light) for longer duration can induce photochemical damage to the macula. These can also cause alteration in physiological functions, alterations in circadian rhythm, and can cause insomnia.^[19] This can also affect the sleep quality, thus causing daytime sleepiness and reduces subjective alertness.^[20]

Extraocular symptoms

Headaches have been shown to be more common when gadgets are used for a prolonged time.^[21] Furthermore, the use of computers causes a constant flexion of neck subsequently leading to back pain, shoulder pain, and neck pain. Wrist, arm, and hands are also affected leading to carpal tunnel syndrome.^[22]

Dry eye disease

For the management of dry eye disease, consistent use of lubricating eye drops has been shown to reduce symptoms of dryness.^[23] Furthermore, the reduced blink rate, as noticed in patients with computer vision syndrome, can be increased by application of air stream to the face.^[14] There is also a positive impact on dry eye disease by closing of eyes for 2 seconds (sec) 2 times in between.^[24] Dietary supplementation of omega-3 fatty acids on dry eye symptoms has shown improvement over a period of three months.^[25] Meta-analysis has stated that overall berry extracts supplementation did not improve visual fatigue.^[26]

Correction of refractive errors and presbyopia

Prolonged viewing of small fonts should be avoided and a minimum viewing distance of 500–635 mm and preferred screen angle of 120–125° horizontally or about 30° below the line of sight is recommended.^[27]

Furthermore, the use of computer glasses has been effective in reduction of vision-related symptoms of computer users.^[28] Supplementary breaks reliably minimize discomfort without impairing productivity.^[29] According to the 20–20–20 rule, every 20 min, one should take the eyes off the screen for 20 sec and focus on an object 20 feet apart.^[30]

Exposure to blue light

Van der Lely et al. suggested the role of blue blocker glasses in male adolescents.^[20] While exposure to LED screen can attenuate melatonin suppression, use of glasses, thus have beneficial effects on sleep quality, daytime functioning, and mood.