BENGALURU: For those whom it is impossible to avoid smartphone or screens or switching off because of their profession, what can they do to ensure that their eyes are in healthy condition? Some important factors in preventing or reducing the symptoms of ‘Computer Vision Syndrome (CVS)’ or Smartphone Vision Syndrome (SVS) have to do with the computer and smartphone and how it is used. This includes lighting conditions, chair comfort, location of reference materials, the position of the monitor, and the use of rest breaks.
Location of the screen
Most people find it more comfortable to view a smartphone with the eyes looking downward. Optimally, the screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) or at eye level.
Lighting
Position the screen to avoid glare, particularly from overhead lighting or windows. Use blinds or drapes on windows and replace the light bulbs in desk lamps with bulbs of lower wattage.
Anti-glare glasses
If there is no way to minimise glare from light sources, consider using anti-glare glasses. These filters decrease the amount of light reflected from the screen.
Rest breaks
To prevent eyestrain, try to rest your eyes when using the smartphone for long periods. Rest your eyes for 15 minutes after two hours of continuous phone use. Also, for every 20 minutes of screen viewing, look into the distance for 20 seconds to allow the eyes a chance to refocus.
Take alternative breaks
After working on the smartphone or computer for an extended period, do anything in which the eyes don’t have to focus on something up close.
Blink
To minimise the chances of developing dry eye when using a smartphone or computer, try to blink frequently. Blinking keeps the front surface of the eye moist.
● Regular eye examinations and proper viewing habits can help to prevent or reduce the development of the symptoms associated with CVS or SVS.
Ideal screen time
There is no such data, but some studies suggest less than three hours per day and that too not at a stretch.
Who is at risk?
Are those who use more than 3-4 hours? For instance, there are people who have 12-16 hours screen time every day. Are they at risk?
Yes, keeping the screen close to your eyes (less than arm and forearm length) is prone to the development of SVS. People wearing spectacles are less associated with it. Age >14 years, male sex, smarphone preference over other digital devices, use of digital devices >5 hours, and use of mobile games >1 hour/day were found to be risk factors for SVS.
What are additional problems that come with this syndrome? Is there a way to detect these symptoms at an early stage?
Symptoms
1) Symptoms related to accommodation (blurred vision for near objects, headache, and eyestrain)
2) Symptoms related to dryness (burning sensation, foreign body sensation, itching, watering, intolerance to light).
The blue light from the smartphone screen is thought to affect central vision as it kills photoreceptor cells in the retina. Once these cells die, they cannot regenerate. This means that any damage done to them is permanent.
Prevention or reduction of vision problems associated with SVS or digital eyestrain involves taking steps to control lighting and glare on the device screen, establishing proper working distances and posture for screen viewing and assuring that even minor vision problems are properly corrected.
The overuse of smartphones could be precursor of raised intraocular pressure and irreversible loss of vision due to glaucoma.
Regular eye check-ups will help in identifying early.
(The writer is consultant - neurology, Fortis Hospital, Bannerghatta Road)