REVIEW ARTICLE
Year : 2015 | Volume
: 20 | Issue : 2 | Page : 134--136
Ocular problems of computer vision syndrome: Review
Ayakutty Muni Raja, Siddharam S Janti, Charanya Chendilnathan, Metheen Adnan
Department of Ophthalmology, Chettinad Hospital and Research Institute, Chennai, Tamil Nadu, India
Correspondence Address:
Ayakutty Muni Raja
19 Lake View Road, Brindhavan Apartments, Flat No. 5, Brindhavan Nagar, Adambakkam, Chennai - 600 088, Tamil Nadu
India
Abstract
Nowadays, ophthalmologists are facing a new group of patients having eye problems related to prolonged and excessive computer use. When the demand for near work exceeds the normal ability of the eye to perform the job comfortably, one develops discomfort and prolonged exposure, which leads to a cascade of reactions that can be put together as computer vision syndrome (CVS). In India, the computer-using population is more than 40 million, and 80% have discomfort due to CVS. Eye strain, headache, blurring of vision and dryness are the most common symptoms. Workstation modification, voluntary blinking, adjustment of the brightness of screen and breaks in between can reduce CVS.
How to cite this article:
Raja AM, Janti SS, Chendilnathan C, Adnan M. Ocular problems of computer vision syndrome: Review.J Mahatma Gandhi Inst Med Sci 2015;20:134-136
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How to cite this URL:
Raja AM, Janti SS, Chendilnathan C, Adnan M. Ocular problems of computer vision syndrome: Review. J Mahatma Gandhi Inst Med Sci [serial online] 2015 [cited 2023 Mar 30 ];20:134-136
Available from: https://www.jmgims.co.in/text.asp?2015/20/2/134/164236 |
Full Text
Introduction
The computer was invented by Charles Babbage in 1791 and, in India, the first computer was used in the Indian Statistical Institute in Calcutta in 1956. [1] The Indian National Survey (INS) was conducted in December 2013, which says that the total number of computer users in India was 150,000,000. [2] We cannot think of a modern world without computers and dependence is rising with time. This has lead to numerous disorders in human beings, of which ocular manifestations play a prominent role. Previously performed studies reveal that the awareness of ocular manifestation is less than 20%. Because of the prolonged and excessive use of computers, ophthalmologists are nowadays faced with a new group of patients who suffer from eye problems. These groups of symptoms are known as computer vision syndrome (CVS).
Definition
The American Optometric Association defines CVS as "The complex of eye and visual problems experienced during or related to Computer use." [3] It is a repetitive strain disorder [4] that appears to be growing rapidly, with some studies estimating that 90% of the workers using computers for more than 3 h/day experience CVS in some form.
The computer-using population in India is more than 40 million, and 80% of them have discomfort due to CVS. [4] The National Institute of Occupational Safety and Health survey has reported that visual symptoms occur in 75-90% as opposed to 22% musculoskeletal disorders of video display terminals workers. [5],[6],[7]
What causes computer vision syndrome?
The human eye was designed for more of distance work, but as we sailed through centuries, with minimal difficulties, the eyes could adapt to the changes in our near tasks. The shift from paper to computers has been so rapid and strong that the eye has not got adapted to the new demands to work in a new reduced distance visual environment for extensive hours. Our eyes and brain react differently to characters on the screen than they do to printed characters. [8],[9]
Healthy eyes can easily maintain focus on the printed page, but characters on a computer screen however do not have this contrast or well-defined edges. These characters (pixels) are brightest at the center and diminish in intensity toward their edges. This makes it very difficult for our eyes to maintain focus and remain fixed on these images. Instead, our eyes tend to drift out to a point called "Resting Point of Accommodation (RPA)," which is approximately 30 inches, and grows as we get older. Prolonged viewing of the monitor closer than your RPA increases eye strain. The ciliary muscle should work 2.5-times harder to focus a monitor 12 inches away than it does to focus at 30 inches. [10],[11]
When the demand for near work exceeds the normal ability of the eye to perform the job comfortably, one develops discomfort and prolonged exposure, leads to a cascade of reactions that can be put together as CVS. Near work here refers to the use of all self-illuminating PCs, mobile phones and the latest gadgets that have helped bring the World Wide Web and quick computation to our hands.
Symptoms of CVS are eyestrain/tiredness, headache, blurring of vision, dryness and irritation of the eyes, redness, contact lens discomfort and neck, shoulder and backache. Predisposing factors for CVS are poor workstation setup or improper use of workstation, uncorrected spectacle power, work-related stress and reduced blinking rate. [12] Blink reflex facilitates resurfacing of the pre-corneal tear film. The normal blinking rate is 12-15 times/min, and it is 60% less with people working on the computer. [3]
Management of computer vision syndrome
Modifications in the computer work station
The chair: A good chair must accommodate all body sizes and must be adjustable in the following areas. [13]
Height of the seat: The feet should rest comfortably on the floor, at a 90 degree angle between the upper and lower legs. [14]
Backrest: The backrest must support the area from the upper ridge of the pelvis to the shoulder blades. The curve in the backrest must support the hollow in the lower back.
Lighting: Ideal lighting conditions should be between 180 and 460 lux levels. Good lighting design can significantly help reduce discomfort due to glare. Wearing a visor is an efficient way to eliminate the brightness of overhead fixtures.
Computer design
Several methods to eliminate the screen reflections anti-reflection coating, etching the glass screen, polarization filter, micromesh filter, tube shield and filter panel should be used in the computers. A polarized screen decreases reflections but not the quality of print and is hence recommended.
Place the screen further away as eye strain tends to increase as tasks are closer. Twenty to 28 inches from your eyes would be ideal. Design the workstation to place the screen at least a few inches below the eye level and eliminate reflections from the screen. Do not have the screen excessively bright. Give your eyes a break by frequently looking away from your monitor for a few seconds. Take short breaks every 20 min for 20 s and look away 20 feet. This is known as the 20-20-20 rule. [5] Computer glasses - Meticulous correction of even the smallest refractive errors is essential. Even a ±0.25 D differences in prescription can be significant in CVS as the visual demand of this task is so high. These glasses can help us to focus more accurately with less effort. Bifocal computer glasses with upper segment set for monitor and lower segment for keyboard or desktop are available. Tinted lenses and anti-reflection coating will prevent glare and reflections.
Artificial tears
Artificial tears form the main stay of management of dry eye in CVS. Two types of artificial tears are available - Preservative free and those containing preservatives. Preservatives are added to artificial tears to prevent contamination of the eye drops on storage.
Recommendations
Nine steps to reduce computer eyestrain have been suggested by the National Institute of Health and Occupational Safety [7] :
Regular, yearly complete eye examination.Use proper lighting.Minimize glare.Adjust the brightness of the computer screen.Take frequent breaks.Refocus your eyes.Blink more often.Modify the workstation.Exercise even while sitting.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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