Computer vision syndrome

Computer Vision Syndrome

Dry Eye Syndrome and other Eye problems due to use of computer , Laptop and Mobile phone.

A Presentation By Surya Prajapat

What is Computer Vision Syndrome?

Computer Vision Syndrome (CVS) is the general term

used to describe a variety of vision related symptoms

that may be aggravated by regular use of a computer

for two or more hours a day.

The longer the use of computer

leads to a decrease in blink reflex.

• This means that while working using a computer, we tend not to blink as often as we should.

• Normal Blink rate : 16-20 per minute.

• During computer use, blink rate : to 6-8 per minute.

Blinking is critically important for spreading of tears to form an even film on the eye surface and also in refreshing this tear film.

Thus in the absence of adequate blinking, eyes become dry and irritated.

Why Computer & like devices are culprit????

• When we look in the distance, our eyes are relatively relaxed and at rest.

• But when we look at computer continuously :

Characters (pixels) on computer screen do not have well defined edges. They are brightest at the center and diminish in intensity towards the edges.

• This makes it very difficult for eyes to maintain focus.

Extensive focusing does not give much opportunity to the eye muscles to move and this leads to eye strain, burning, tired – eyes feeling.

a. Poor position in relation to computer

Causes of Computer Vision Syndrome

Other contributing factors

Constant gazing at a near distance at the monitor (which leads to convergence fatigue).

• Fixed posture while working long hours

• The eye muscles do not get much opportunity to move.

• Uncorrected visual defects

• Glare from lighting in the work place and direct light coming in from the exterior

Symptoms of CVS

Symptoms…….

Prevention or Things to be done to minimize CVS• To begin, anyone who suspects CVS should have a

Thorough eye examination by an Ophthalmologist

• Apart from this, a few additional steps can help reduce CVS

Blink more OftenComputer users should make a conscious effort to blink more often:

• They should try the suggested formula

20 : 20 : 20

Every 20 mins : look 20 feet : for 20 secs

Adjusting height of the seat and Computer screen distance from eye

Adjust the height of the desk or chair so that the middle of the computer screen is about 20 degree below eye level.

Reduce glare

• Direct the overhead lights away from computer screens.

• Position your monitor so that all windows are to the side rather than to the back or front.

• Adjust window blinds so that sunlight is away from screen and your eyes

Take a BreakComputer users can reduce fatigue by taking breaks from work and can benefit from taking a five minute break for every 30 mins of work.

Avoid air draftsAvoid siting in front of an air conditioner facing its air

draft while working on computer.

Dry Eye due to Computer Vision SyndromeWhen working on Computer or mobile phone for a longer duration, following eye problems may occur :

1. feeling of dryness, grittiness, burning, itchiness or scratchiness of the eyes

2. sensitivity to light

3. blurred vision

4. excessive tear flow (caused by an imbalance in the tear film)

• This usually happens because of a deficiency in the aqueous component of the tear film or an increase in tear evaporation, or a combination of these events.

The normal tear film The dry eye tear film

Clinical Test of Severity Units Parameters Reported

Functional TestsEvaporimetry g/cm2/sec Evaporation rate

Schimer Test mm Tear productionOptical scattering OSI Visual stability

TBUT seconds Tear StabilityInterferometry um Lipid Layer thicknessBlink rate blinks/min Tear Stability (indirect)

Molecular Tests

Tear Osmolarity mOsm/L Tear concentration and stabilityMMP-9 ug/ml inflammation

Cytokine profiles (IL-1, etc) pg/ml inflammation

Lactoferrin/Lysozyme mg/ml Tear production

Subjective Tests

Corneal staining grade 0-4 Damage (mucin deficiency)Conjunctival staining grade 0-4 Tissue Damage

MGD grading grade 0-28 Gland obstruction and inflammation

Symptoms (OSDI) score 0-100 Discomfort

Diagnosis Various Clinical Biomarkers of Dry EyeDisease Severity

Thank You

A Presentation By Surya Prajapat