People who are so addicted to smartphones they may be increasing their risk of eye damage.

Opticians warn that overuse from phones and other devices such as computers, tablets, and flat screen TVs can lead to long-term damage.

Andy Hepworth, a UK-based optician said: "Blue violet light is potentially hazardous and toxic to the back of your eyes.

It’s the combination of not blinking enough and bringing the device closer than you normally look at objects, it strains your eyes, Hepworth added.

"So over a long period of time it can potentially damage your eyes. When you’re looking at a smart phone, the light peaking out of that is blue violet.”

He says tests have found that over exposure to blue-violet light has the potential to put us at greater risk of macular degeneration, a leading cause of blindness.

Opticians say although "good” blue light (blue-turquoise) is needed to help regulate biological clocks, it is also thought that extensive exposure to blue violet light can disrupting sleep patterns and affect moods.

"Although we don’t know if there’s a direct link with it creating eye problems, there is strong lab evidence it can potentially do that,” Hepworth added.

"It’s the combination of not blinking enough and bringing the device closer than you normally look at objects that strains your eyes.”

‘More headaches’

It comes after  a survey (conducted in the UK) that found that on average, an adult spends nearly seven hours a day staring at a screen with nearly half feeling anxious when away from their phone.

Statistics also suggest 43 per cent of under 25s experience genuine irritation or anxiety when they can’t check their phone when they want.

It also found 55 per cent felt the amount of screen time they’re exposed to affects them with eye discomfort the main problem. 

Dr Ashvin  Agarwal , a cornea and refractive surgeon at Dr Agarwal Eye Hospital in Kigali, admitted that over exposure to gadgets like computers and smart phones causes a complication called "dry eye syndrome " since the liquid in the eye evaporates, hence causing blurred vision in the long run.

Dr John Nkurikiye, an ophthalmologist working with Dr Agarwal’s Eye Hospital, differed, saying there was need to carry out more research before a conclusion can be made.

"Light emitted by gadgets like computers and smart phones only causes temporary itching if one is over exposed, but doesn’t cause defect,” Nkurikiye said.

His compatriot at King Faisal Hospital, Rwanda, Dr Francis Mutangana, said light from such gadgets does not damage vision.

However, Dr Mutangana added that to avoid eye irritation, one has to take frequent breaks of at least 20 minutes every hour from their gadget.