As someone who suffers from computer eye strain, I was alarmed to discover that prolonged exposure to gadgets such as iPhones and iPads can cause irreversible damage to the eyes. A Spanish expert, Dr Celia Sanchez-Ramos, has found the LED screens found in most electronic devices can harm the retina - the light-sensitive layer at the back of the eye - and may even lead to partial blindness. Research has already shown that the intense levels of 'blue light' emitted from modern gadgets can cause a variety of health complaints, ranging from sleeping and eating problems to headaches and even cancer. Scroll down for video . LED screens found in most electronic devices such as iPhones and tablets can harm the retina - the light-sensitive layer at the back of the eye - and may even lead to partial blindness, a doctor has warned . Now, Dr Sanchez-Ramos has discovered that it can also permanently damage the retina. In extreme cases, she says, it may even lead to macular degeneration, which causes dark patches to appear in the centre of the field of vision. According to Dr Sanchez-Ramos, modern LED screens, produced from about 2007 onwards, emit up to five times as much blue light as older technology. This matches my own experience, in which pre-2007 screens tend not to cause discomfort. The average adult now spends up to eight-and-a-half hours in front of a screen every day, and it is not uncommon to be exposed to multiple screens at once. For these reasons, says Dr Sanchez-Ramos, who is based at Complutense University in Madrid, the majority of people are likely to be in the danger zone. Children and the elderly are most at risk on account of their delicate eyes, as well as 'digital workers' and those - like me - who are especially sensitive to blue light. Dr Sanchez-Ramos (pictured) said: 'Never before in human history have we exposed our eyes to light that is so intense, for such long periods, from such an early age' 'Never before in human history have we exposed our eyes to light that is so intense, for such long periods, from such an early age,' she says. 'People who suffer from eye strain are like the canaries in the mineshaft, as they are aware of the damage being done. But it can affect anybody.' The damage, she explains, starts when the photoreceptors - types of neurone found in the retina that convert light into information - begin to die out due to the prolonged saturation of blue light. This puts strain on other parts of the eye, leading to increasing levels of inflammation, discomfort and pain. Eventually, the concentration of blue light in the centre of the retina, an area known as the macula, may cause it to be permanently damaged, leading to visual disorders. However the problem can be remedied by using special screen filters or glasses designed to block blue light, which are available through opticians. Daniel Hardiman-McCartney, clinical adviser at the College of Optometrists, says: 'It has been proven that intense exposure to blue light kills cells in the retina, and it is a perfectly reasonable possibility that it can cause macular degeneration over a period of time. 'More research is needed to prove it to the scientific standard. We need to conduct studies on a large number of people over a long period of time. 'But the proposal is of great interest.' Dr Sanchez-Ramos carried out experiments at the University of Madrid in which human retinal cells, taken from volunteers, were exposed to cycles of LED light of different intensities. She found that exposure to intense blue light caused apoptosis, or cell death. However this was reduced by 83 per cent when a special protective filter was placed between the cells and the light. Based on this research, she designed a screen filter called ' Reticare ', which converts harmful blue light to a gentler frequency more akin to sunshine. Dr Sanchez-Ramos found that exposure to intense blue light caused cell death in the eye. However this was reduced by 83 per cent when a special protective filter was placed between the cells and the light . Her findings prompted her to design a screen filter called ' Reticare ', which converts harmful blue light to a gentler frequency more akin to sunshine . Other treatments are also available. In 2013, Barnard Levit optometrists in London, who are specialists in the field, tested my eyes using a machine called a Colorimeter. Following this, they designed a pair of glasses with a blue tint, which blocked the most harmful part of the colour spectrum. The harmful effects of exposure to gadgets is linked to the high levels of 'blue light', also known as 'short wavelength light', that is emitted by modern screens. According to researchers at Harvard Medical School , 'not all colours of light have the same effect'. In particular, blue wavelengths, which are emitted by most electronic devices produced from 2007 onwards, have been shown to have 'adverse health effects'. Modern LED screens emit up to five times as much blue light as older technology. Researchers have found that using an electronic gadget with a backlit display for just two hours can affect the production of melatonin - the chemical that controls our body clock - and cause sleep problems, particularly in teenagers. A study at Chicago's Northwestern University revealed that prolonged exposure to blue light stimulated the sensation of hunger, even directly after meals, making it a contributor to weight gain and obesity. And experts at the University of Connecticut found a link between cancer and the use of gadgets that emit blue light in the evenings and by night. In addition, Dr Sanchez-Ramos has found that exposure to blue light can damage the retina causing macular degeration, or partial blindness. Children and young adults are at greater risk, as they lack the natural protection against blue light that the human eye naturally acquires. The effects can be reduced by the use of protective filters or spectacles. Prior to this, I had been unable to use iPhones, iPads and other gadgets with LED screens without shooting pain in my eyes, dizziness and nausea. This condition is known as Meares-Irlen syndrome or 'visual stress'. It is thought to be caused by hypersensitivity to particular frequencies of light, whether blue, red or green. In response, the visual cortex - the part of the brain responsible for processing visual information - generates too much electrical activity. This spills over into different areas of the brain, causing a variety of symptoms. About 10 per cent of people with dyslexia are thought to have visual stress. It can also be found in those with autism, ADHD, migraine, photo-sensitive epilepsy and multiple sclerosis, as well as stroke victims. Unusually for a sufferer of the condition, I have none of the related conditions listed above. When I used the blue glasses, however, I found that my eye pain, dizziness and nausea all but disappeared when using LED screens. I later discovered the glasses did not work with every type of screen, possibly because some emit different frequencies of harmful light. When I road-tested one of Dr Sanchez-Ramos' filters, I found my symptoms were reduced significantly on all devices, though the blue spectacles were more effective with certain screens. Dr Sanchez-Ramos says the use of LED screens has become so ubiquitous in such a short period of time that in 20 years' time, severe eye problems could become widespread. She and her colleagues are lobbying Apple, Samsung and other technology manufacturers to make their screens friendlier to the eye, meaning that no protective filters would be needed. This, she says, is an uphill struggle because super-bright screens make more of an impact on the customer, which encourages sales. She has also been putting pressure on various European governments, on both a national and regional level. As a result, a number of Spanish local authorities have ruled that all schools under their jurisdiction must use protective screen filters. Reticare filters are now available online and cost between €12.95 and €49, depending on the size of the screen.
Key culprit is the LED screens found in most electronic devices . These can can harm the light-sensitive retina, irreversibly damaging sight . However the problem can be remedied by using special screen filters . Dr Celia Sanchez-Ramos has developed one to make light less damaging .