Unfortunately, we know that all the organs and tissues of our body are aging. Over the years, the skin becomes wrinkled and loses its elasticity, the joints are seized, the spine gets stuck, the blood vessels become less permeable, the heart contracts more slowly ...

The eyes, of course, do not escape the rule. On the contrary.

Organs in constant stimulation

Over-stimulated from morning to night, they are among the great victims of modern life.

They suffer not only from pollution, but also the intensive use of light screens (computers, digital tablets, smartphones, television ...).

"We are witnessing an explosion of eye disorders," says Professor Jean-François Korobelnik, president of the French Society of Ophthalmology (SFO) and head of department at Pellegrin Hospital in Bordeaux. The inventory is indeed amazing.

In East Asia, myopia is an epidemic. A third of the Chinese population is now affected. And it's even worse for young people: more than 80% of students are nearsighted by the end of high school, 20% of them with very severe forms that can lead to blindness. It is the same in Japan and South Korea.

In Europe, the numbers are less catastrophic, but the contagion undoubtedly gains.

The falling view, the evil of the century

Among 12-54 year olds, the prevalence of myopia is now 40% on the Old Continent, against 20% in the early seventies.

In France, more than a quarter of young people suffer from this accommodation disorder, 5% of whom are heavy. While it is increasingly difficult to get an appointment with an ophthalmologist (three months on average and up to seven months in some regions ¹ ), diseases of the retina are progressing even more impressively .

Age-related macular degeneration (AMD), which has become the leading cause of low vision in France , should double its number of victims in the next 20 years: 3 million people affected in 2020, against 1.5 million in 2000 according to the French Academy of Ophthalmology. As for glaucoma , optic nerve disease whose occurrence is favored by a high myopia, they will also make a big leap forward ( 70% of cases), just like cataracts ( 78%) or retinopathies ( 100% ). How to explain this terrible wave?

Half of eye disorders caused by lifestyle

"Certainly, heredity plays a role, says Professor Jean-François Korobelnik, but it seems that half of these disabilities results from our lifestyles . To remain confined in buildings all day long would be, for example, detrimental to our eyes.

According to an October 2012 study conducted at the University of Cambridge (Great Britain), only 3.3% of 6-7-year-old children of Chinese origin living in Australia suffer from myopia, compared to 29% of those of the same age residing in Singapore.

The main difference between them: the first practice nearly fourteen hours of outdoor activities per week, while the latter only three. Their retina, deprived of natural light, produces less dopamine, which could stimulate the growth of eyeballs. Now, a myopic eye is an eye too long: the image is formed in front of the retina, and not on this one. In addition, " spending more time outdoors requires less close vision ," says Professor Korobelnik. We look away instead of stuck to his books or a screen ".

Each additional weekly hour in the open air would reduce the risk by about 2%.

By the way, that says little sun exposure of the skin also says potential vitamin D deficiency . And it seems that a deficiency in this vitamin is likely to accelerate the degeneration of the visual cells.

Researchers at the Institute of Ophthalmology at the University of London made it clear in February 2012 about deficient mice. By providing them with regular vitamin D supplementation, they have been able to quickly stop the development of age-related eye diseases.

Knowing that two out of three adults lack vitamin D in France, especially urban dwellers living north of the Loire, we have every interest to ventilate more, at least a good half hour per day. And failing that, to absorb a vitamin D ampoule every two months to fill a possible deficit.

New risk factors

Some lights are also incriminated, especially those LED (light emitting diodes) insofar as they emit blue light .

" Near ultra-violet, these very energetic radiations attack the retina . They induce oxidative stress by interacting with the pigments contained in the photoreceptors of the eye, explains Dr. Francine Behar-Cohen, an ophthalmologist at the Hôtel-Dieu hospital in Paris. This induces the release of free radicals that may worsen or trigger AMD in susceptible individuals. "

In August 2013, researchers from the Institute of Vision in Paris, in fact, proved that a fraction of the blue light destroyed the cells of the retina in animals. As LED lamps become more common because of their low power consumption and long life, caution is required ² . Especially as some computers, TVs and game consoles contain too.

Another risk factor: our modern diet unbalanced, too rich in meat, sugar and cereals.

"Inadequate consumption of omega 3 fatty acids, found particularly in nuts and oily fishes, favors the alteration of the optic nerve responsible for glaucoma," says Pr Jean-Paul Renard, ophthalmologist at the hospital of Val-de-Grâce in Paris.

Junk food is also a source of AMD. Low contributions of antioxidants - vitamins C and E, zinc and carotenoids - do not allow the retina to effectively fight against the attack of free radicals. Egg yolks, seafood, colorful fruits and vegetables are therefore regularly added to the menu to preserve our visual capital.

Repeated exposure to insecticides and herbicides is also singled out . As Renard says: "Several recent studies, including one conducted in the Bordeaux region on more than 600 vine growers, have established a close link between pesticides and the occurrence of glaucoma. "

To meditate before sprinkling your green plants or flowerbeds with chemicals.

New innovative treatments for eyesight

But no need to panic more than reason.

For while the epidemic of visual diseases is progressing, ophthalmology is starting a real revolution. This is one of the medical specialties that has made the most good technology in the last fifteen years. After the development of innovative treatments for corneal and crystalline disorders (refractive laser surgery to correct myopia, astigmatism or presbyopia, corrective implants to treat cataract associated with lack of accommodation ...), new horizons are opening up to cure deep ocular pathologies, those which touch the back of the eye and remain without definitive remedy, or almost.

This is the case of glaucoma recalcitrant conventional therapies that we have not managed so far to block evolution. In the absence of a suitable therapeutic weapon, the excess of intraocular pressure due to the accumulation of liquid ended up narrowing the field of vision to skin of sorrow. This page now seems turned thanks to the ultrasound that allows to operate the eye without having recourse to the knife.

"To treat glaucoma, we use eye drops containing prostaglandins or beta-blockers in the initial stage to reduce pressure," says Dr. Eric Sellem of the Kleber ophthalmic center in Lyon.

Certain forms of acute glaucoma can also benefit from laser treatment under local anesthesia.

"The results are satisfactory, but the effect is not sustainable: the operation must be renewed every three to four years," says the doctor. Resistant glaucomas are eligible for surgery: an incision is made under the eyelid in the wall of the eye so that the liquid can flow. In 80% of cases, the evolution of the disease is slowed down. But there are risks of infection, haemorrhage and cataracts. And 20% of patients unfortunately do recurrence. Hence the interest of ultrasound.

"By destroying the ciliary body that produces the aqueous humor, they definitely normalize eye strain in a single session in many patients," says Dr. Eric Sellem. An unprecedented step forward! The icing on the cake: the intervention lasts only two minutes and is painless. The technology is still nascent, but a dozen hospitals are already using it today. Thousands of blindness can be avoided.

Eye diseases: stem cells and implants

Restoring the functionality of a retina damaged by age-related macular degeneration also seems to be no longer science fiction.

Still unthinkable just three years ago, this feat is starting to come true. The principle is based on the injection of stem cells derived from embryos or taken from the patient himself. Once programmed to become light receptor cells (cones or rods), they are injected into the retina to be repaired. And, miraculously, they are lodged exactly in the right place to replace the cells out of order.

The first transplant of this type was successfully performed at the Jules-Stein Institute in Los Angeles in 2011. Since then, about twenty other patients have been operated on in the United States and Great Britain. Although there is still not enough perspective to know if their healing is definitive, most of them are greatly satisfied: their visual abilities, previously reduced to nothing, have been partially restored. Further trials are planned on a larger number of individuals to perfect the protocol. A hope for a million and a half French people suffering from this disease for which there are still no effective drugs.

Bionic implants , intended for patients suffering from genetic retinopathy that has destroyed their retina, are already proving their worth. Nearly a hundred people who have become blind have already benefited, including four in France. Like real prostheses, they perform the work of deteriorated photoreceptors: they perceive the luminous images and convert them into signals that the brain is able to interpret. A mini-camera, attached to a pair of glasses, films the images and then transforms them into electrical impulses then sent by radio wave to the chip implanted at the bottom of the patient's eye. The result is spectacular: thanks to this clever equipment, distinguish small objects in a room, decipher a store sign or read a few lines becomes possible!

Artificial retinas fully implantable, therefore less restrictive, are under development. By 2020, many retinopaths are expected to recover the sight of their 20s.

Towards smart lenses

Other ingenious devices are emerging, such as a high-tech soft contact lens intended not to correct a disturbance of accommodation but to measure the intraocular pressure.

Tested in the ophthalmology department of the University Hospital of Grenoble, it detects minute changes in the circumference of the eye that occur when the pressure increases inside. The data collected is transmitted by a miniature antenna to a portable recorder the size of an iPhone. Ideal for detecting a glaucoma stammering or to check for a few days the effectiveness of a treatment.

Internet giant Google is working on a lens that can measure the concentration of tears in glucose.

Objective: to continuously monitor the blood sugar levels of diabetic patients, in order to free them from this unpleasant chore (measured three to five times a day in a drop of blood taken at the end of the finger). If the rate deviates from the desired standard, an alarm sounds. The patient knows illico that he must proceed with his injection of insulin. No more forgetfulness! More imaginative, a pharmacist lens, being studied at Harvard University. On its inner side is a thin film of polymer that encapsulates drugs released gradually on the cornea in contact with the eye. The first tests, carried out on cells cultured in the laboratory and on animals, indicate that the quantity of active ingredients salted out is stable over time and that it is equivalent to that distilled by eye drops. Terribly clever to treat glaucoma or ophthalmic infection.

What you may not know about your eyes

• UV station in summer

" The harmful effects of UV on the eyes are daunting , warns Professor Francine Behar-Cohen. They cause premature aging of the cornea, lens and retina. That's why sunglasses should not be seen as just one fashion accessory. Do not be fooled by the color of the glasses. Only the CE logo, indelibly printed, is the guarantee of effective protection. Also check that they guarantee the filtration of UVA and UVB (E-SPF index), ideally on the front and back of the glasses. As for sun creams, the higher the index, the better the protection. On vacation, a 50 index is required. As for the choice of frames, opt for a wraparound model so that the rays do not pass above, below or on the sides. But by car, thin branches are preferable to not obstruct the side vision.

• Winning foods

Green cabbages, spinach, turnips, zucchini, peppers, corn, mangoes and broccoli are good for the eyes thanks to their high content of lutein and zeaxanthin, two antioxidants from the carotenoid family that slow the premature aging of the retina. As Japanese researchers at Keio University have shown, they reduce the risk of AMD. Black berries (blueberries, blackcurrants, blackberries) are also protective because of their concentration in anthocyanins, pigments that act as sunscreen for our cells. Well supplied with vitamin C, they also preserve the integrity of the lens, which pushes the spectrum of cataracts.

• Men / women, different perceptions

Each genre has a vision of its own. According to a study by neurophysiologist Israel Abramov of Brooklyn College in New York, men are more sensitive to the finer details and visual stimuli in motion than women, but, on the other hand, their perception of color would be less good . This disparity does not come from a difference in anatomy of the eyes but from the density of the visual cortex, the region of the brain that analyzes the images perceived by the retina. That of men, more bathed in testosterone during embryonic development, contains 25% more neurons. An obvious asset at a time when the prosperity if not the survival of a family was based on the talents of a gentleman hunter. But today…

• Sleep well to see well

The link between sleep and eye health does exist. " Obstructive sleep apnea syndrome, which affects more than 500,000 people in France causes abnormal fatigue, cardiovascular disorders, but also serious ophthalmic complications ," said Professor Jean-François Korobelnik. It could be responsible for two thirds of glaucoma with normal intraocular pressure. Now, as many apneists are unaware of each other, their optic nerve is destroyed with low noise. "However, it is enough to improve their nocturnal oxygenation so that glaucoma stops its evolution," says Professor Korobelnik. It is the same for the retinopathy of under-oxygenated diabetics. A track not to neglect.

1. Based on a survey of 2,600 French practitioners published in February 2014 by the Yssup Research Institute.
2. Today, there are photoselective lenses that protect not only UV but also the harmful effects of blue light (Crizal Prevencia).