Opticians London Liverpool Street: Eye Contact , Unit 2, The Arcade, Liverpool Street, London, EC2M 7PN - (t) 0207 626 7232. 2 minutes walk from London Wall, Broadgate
Eye Contact Opticians London - Liverpool Street, Broadgate

Eye strain symptoms

50 – 90% of computer workers complain of eye strain

stock-photo-20490722-the-hustle-and-bustle-of-a-productive-work-environmentUsing a computer screen is visually demanding task and vision problems and symptoms are very common. Some studies reported by the American Optometric Association have found that  90% of computer users suffer symptoms of eye strain, the most common complaint of computer workers. This contrasts with  only 22% of computer workers suffer musculoskeletal disorders according to the US National Institute for Occupational Safety & Health.  Symptoms include:

 

Man looking stressedHeadaches, one of most common causes of short term absence (CBI, 2011) – the main reason people seek an eye examination, visual fatigue related headaches occur towards the end of the day, are of mild to moderate intensity toward the front or side of the head. They typically do not appear on wakening and occur on a different pattern, or not at all, on weekends

 

637_blurred_vision-300x200Blurred vision  – if letters viewed on the screen are not clear then the user will take longer to complete tasks and make more errors. To form a clear image the eye must change its focal power, whether it can be done and whether it can be done easily and reversed again must be mastered to ensure clear and comfortable viewing. If you cannot achieve this easily, you may be suffering a vision defect.

 

rec-irritated-eye-istockphoto-thinkstockphoto-4-23-12-mdDry & irritated eyes – tears that cover the eye surface and keep it moist is cleaned off an refreshed by blinking of the eyelids. Computer workers have been found to have a lower blink rate which is likely be concentration on the task or a relatively limited range of eye movements, compounded by the higher gaze angle resulting in an increased rate of tear evaporation (Nakamori, 1993)

 

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Neck and backache – Nature has made our visual system so dominant that we will alter our body posture to accommodate any deficiency in the way we see.If the vision of a worker is compromised and they must adapt their posture to ease the strain on the visual system (leaning closer to screen). If an older worker is using reading glasses (single vision), which are designed for a 16-inch viewing distance, they must lean in toward a screen that may be 20 to 25 inches away in order to clear the image.

 

Slow refocusing – when viewing a computer screen, like any near object, the point of focus is normally beyond the screen. When the computer worker views tasks for extended period of time, the lag increases and more effort must be expended to pull focussing point back, leading to headache or blurred vision if an underlying vision defect means this cant be done successfully.

Doubling of vision – eyes must be used efficiently together to scan images and pick the one that the task requires and make small jumps at regular intervals when reading. Frequent eye movements are required from work documents to computer screen or from keyboard to screen.When we lose our ability to maintain the “lock” between the eyes, they can misalign and aim at different points in space, which can be experienced as double vision. Often computer worker will experience doubling of vision after using a computer and may not be noticeable until the stress reaches an advanced stage.

“During the week I am using a screen for 10 hours a day and by the end of the day I can’t see the signs at the station and things look out of focus”

Light sensitivity – Eyes are designed to be stimulated by light and to control the amount of light entering the eyeball. Workplace conditions are foreign to the natural lighting environment and can cause an adverse reaction to light. Common for luminance to be 100 times greater than display screen worker is using.