Display Screen Equipment

What is Display Screen Equipment

• device that has alphanumeric or graphic display screen

• includes conventional display screens+laptops, touchscreens etc

Who does the Health and Safety (DSE) Regulations 1992 apply to?

• workers who use DSE daily for more than an hour at a time

Why were DSE regulations introduced?

• to protect healthy of computer users specifically to prevent :

• Discomfort - particularly in back , neck, shoulder, arms and hands

• stress

• Visual discomfort

What is the Employers responsibility in relation to DSE regulations 1992?

• must carry out risk assessment of workstations used by employees to reduce identified risks

• employers must ensure that employees take regular and adequate breaks from looking at their screens

• Employers provide an eye test if a worker asks for one

• Employers provide training and info for workers

What symptoms do office workers experience

• 40% - tired eyes occurring at least half of the time

• other- dry eyes, eye-strain and/or eye discomfort + irritated or burning eyes were experienced

Dry eye and DSE link

• dry eye considered significant aetiology of digital eye strain

• using DSE → altered blinking , environmental influences and angle gaze

• desktop computer screen viewed in horizontal gaze → paplepebral aperture wider than for conventional reading tasks (downward gaze)

• Larger ocular surface exposed to effects of tear evaporation

• wider palpebral aperture = increased evaporation

What is the blink Rate Reduction when using DSE?

Normal conversation ~15-20 blinks/min

Digital device drops to ~4-6 blinks/min

Incomplete blinking result:

• inferior corneal staining and tear film instability

What is the ocular surface management ?

Tear substitution → preservative-free ocular lubricants

Blink exercise → Full, intentional blink training - Advise px to blink more often

Humidifiers in air-conditioned offices

Hydration (systemic)

CL wearers → Advise removing CLs for specific heavy screen days

switch to glasses for DSE work to reduce tear film disruption

Accommodation when using DSE

• Pixels differ from print - eyes struggle to maintain lock

• leading to micro-fluctuations in accommodation

could cause eye fatigue, difficulty refocusing at distance after screen work

Vergence demand - DSE

• sustained convergence at intermediate distances - 50-70cm → can lead to eye strain , difficulty concentrating

• decompensated phorias → small exo managed easily at distance may decompensated at intermediate range after 8 hours

Describe the Standard Workstation Setup

• Top of screen level with your eyes → about arms length away

• Relax your shoulders - position yourself high enough so you don’t shrug your shoulders

• keyboard just below elbow height

• seat height equally supports front and back of thighs

• back of seat provides good Lowe rback support

• Gap of 2-3cm between front of seat bottom and back of knee

• computer screen directly in front of you on desk

• screen and keyboard central - dont twist back

• mouse in line with elbow

Laptop set up

• keyboard and mouse separate from laptop so screen can be elevated on a laptop riser or similar

• Display screen separate from laptop

Ergonomics and VDU

• 20-20-20 Rule

• every 20 mins look at something 20 feet away for 20 seconds

• to relax ciliary muscle and rest vergence

Text size - increase font size to reduce demand

Glare and VDU

• light may be reflected from VDU screen and keyboard

• position of VDU should be adjusted so operator can not see any reflections

• close window blinds + turn off problematic lighting

blue-light glasses

• if selling blue-blocking spectacle lenses ensure px aware that there is no strong evidence that blue-blocking spectacle lenses will improve visual performance , alleviate symptoms of eye fatigue or visual discomfort

When examining px who works with DSE?

• Carry out full eye exam to determine cause

• ask px to describe their workstation and its environment

• give appropriate advice, including ergonomic info, if appropriate

• provide them with prescription or written statement as appropriate

• maintain confidentiality of clinical info at all times - only provides info to employer if relevant and only if obtained consent from px

Case history questions of a DSE user?

• Date of last eye exam

• When VDU work commenced

• How many hours per day on VDU used?

• Are work breaks provided and their duration?

• distance of screen, keyboard and documents

• position of VDU screen

• Reflections of glare sources in view

Health and Safety DSE regulation

• require that employer provide spectacles for a user if they require a different prescription or type of lens for screen use then their normal everyday spectacles

• when a px normal everyday spectacles used for screen use employer not under obligation to pay any thing towards them

Who are the main people who require specific spectacles

• most are presbyopia with higher reading additions who need a pair of intermediate range spectacles to view screen use outside the working range of their reading specs

Patient consent

• px under no obligation to reveal any clinical info to his employer although failure to do so may become employment issue

• Under the DSE regulation , employe only requires:

• confirmation test was performed

• whether or not px requires spectacles, their own specs or special VDU spectacle

• date of next suggested VDU exam