Computer Vision Syndrome: A Review

m e d i c a l j o u r n a l a r m e d f o r c e s i n d i a 7 2 ( 2 0 1 6 ) 2 7 0 -2 7 6 a r t i c l e i n f o The use of these devices has made our life simple in household work as well as in offices.However the prolonged use of these devices is not without any complication. Computer and visual display terminals syndrome is a constellation of symptoms ocular as well as extraocular associated with prolonged use of visual display terminals. This syndrome is gaining importance in this modern era because of the widespread use of technologies in day-to-day life. It is associated with asthenopic symptoms, visual blurring, dry eyes, musculoskeletal symptoms such as neck pain, back pain, shoulder pain, carpal tunnel syndrome, psychosocial factors, venous thromboembolism, shoulder tendonitis, and elbow epicondylitis. Proper identification of symptoms and causative factors are necessary for the accurate diagnosis and management. This article focuses on the various aspects of the computer vision display terminals syndrome described in the previous literature. Further research is needed for the better understanding of the complex pathophysiology and management. #

show abstract

“…These alterations are temporary changes and have no long-term permanent effect on accommodation and convergence. 5 …”

Section: Loss Of Accommodative Amplitude and Vergencementioning

confidence: 99%

Computer and visual display terminals (VDT) vision syndrome (CVDTS)

Parihar

Jain

Chaturvedi

et al. 2016

Medical Journal Armed Forces India

116

122

View full text Add to dashboard Cite

show abstract

“…Extensive use of a computer can lead to either reduced accommodation or over-accommodation resulting in eyestrain. It has also been shown that it reduces the amplitude of accommodation 16 . Prolonged accommodation due to near work, as occurs during extensive computer work, increases the prevalence of myopia or pseudo-myopia 9,16 .…”

mentioning

confidence: 97%

“…It has also been shown that it reduces the amplitude of accommodation 16 . Prolonged accommodation due to near work, as occurs during extensive computer work, increases the prevalence of myopia or pseudo-myopia 9,16 . The quality of the display also affects the accommodative response where a more blurred image will result in a lag of accommodation.…”

mentioning

confidence: 97%

“…The quality of the display also affects the accommodative response where a more blurred image will result in a lag of accommodation. Another factor that reduces the accommodative amplitude is the luminance of the workplace 16 , which explains why it is so important to have appropriate lighting in the work place. Staff should also be encouraged to take breaks regularly in an attempt to help relieve the strain on the visual system 16 .…”

mentioning

confidence: 99%

See 1 more Smart Citation

The near triad and associated visual problems

Emslie

Sachs²,

Claassens

et al. 2007

African Vision and Eye Health

View full text Add to dashboard Cite

When a person changes fixation from one target, at a given fixation distance, to another target, at an alternate fixation distance, a number of ocular systems need to be altered in order to maintain clear single binocular vision. One such system is that of accommodation, involving either positive or negative accommodation 1 . When viewing an object at six meters, a distance known optometrically as optical infinity, it is assumed that parallel light rays enter the eye. For an emmetrope this results in zero accommodative demand and therefore zero accommodation. When viewing an object closer than 6 meters positive accommodation is required. This involves intraocular lens changes which ultimately increase the refractive power of the eye, allowing the rays to form a point focus on the retina. The opposite process, negative accommodation, occurs when an object is fixated further away from some near fixation point. Accommodation can therefore be thought of as the process by which the refractive power of the eye is altered to ensure a clear retinal image 1 .It should also be noted that a change in the position of the visual axes must also take place 1 . This occurs to ensure that a single image of the target is seen. The change in relative position of the visual axis is called convergence when the angle formed by the visual axes increases, and divergence when this angle decreases 1 .When a person fixates a near target an additional process takes place, that is, pupillary constriction. This occurs together with accommodation and convergence, and alters the depth of focus 1 . These three sub-systems work together as a synkinesis known as the near triad 1, 2 .One should not forget the fact that the processes mentioned above are very complex and involve numerous pathways, the details of which are little known. As a result it is easy to understand that many problems can occur in each process, resulting in visual problems. This paper serves to address some of those visual problems. AccommodationThe amplitude of accommodation represents the closest near focusing response that can be produced with maximal voluntary effort in the fully corrected eye 2 . From around five years of age to around 52 years of age, the accommodative amplitude progressively decreases at a rate of approximately 0.30 D per year 2 . Various theorists attribute the loss of accommodation to changes in the elastic properties of the lens, changes in the action of the ciliary muscle, or both 3 . The anterior chamber depth, shape of the lens, refractive index and position of the lens surfaces change with age, affecting the accommodative process 4 . This leads to the development of presbyopia. The amplitude of accommodation inevitably decreases from 11 D or more at age 10 to nearly 0 D by age 70 years. This means that an emmetropic child can focus an object as close as 10 cm, while an older adult must move objects at least a metre or more away to see them clearly 3 . †

show abstract

“…For instance, studies have shown that news websites lead to rapid and shallow reading, while printed newspapers encourage effortful learning (Ackerman & Goldsmith, 2011;Mangen, Walgermo, & Brønnick, 2013). This difference is likely reliant on a number of variables, such as metacognitive beliefs about the medium, ergonomics, preexisting knowledge, or the ability and motivation to process news (e.g., Ackerman & Goldsmith, 2011;Blehm, Vishnu, Khattak, Mitra, & Yee, 2005;Mangen et al, 2013;Rhee & Cappella, 1997). Yet, we want to highlight another relevant mediator variable: visual attention to news content as an observable predecessor and likely predictor of news processing and learning (Eveland, 2001).…”

mentioning

confidence: 99%