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HEALTH

Scientists in France say they’ve found a cause of dyslexia

Two French scientists from Brittany say they've made a breakthrough in the search to find the cause of dyslexia.

A duo of French scientists said Wednesday they may have found a physiological, and seemingly treatable, cause for dyslexia hidden in tiny light-receptor cells in the human eye.

In people with the reading disability, the cells were arranged in matching patterns in both eyes, which may be to blame for confusing the brain by
producing “mirror” images, the co-authors wrote in the journal Proceedings of the Royal Society B.

In non-dyslexic people, the cells are arranged asymmetrically, allowing signals from the one eye to be overridden by the other to create a single image in the brain.

“Our observations lead us to believe that we indeed found a potential cause of dyslexia,” study co-author Guy Ropars of the University of Rennes, told AFP.

It offers a “relatively simple” method of diagnosis, he added, by simply looking into a subject's eyes.

Furthermore, “the discovery of a delay (of about 10 thousandths of a second) between the primary image and the mirror image in the opposing hemispheres of the brain, allowed us to develop a method to erase the mirror image that is so confusing for dyslexic people” — using an LED lamp.

Like being left- or right-handed, human beings also have a dominant eye.

As most of us have two eyes, which record slightly different versions of the same image, the brain has to select one of the two, creating a
“non-symmetry.”

Many more people are right-eyed than left, and the dominant eye has more neural connections to the brain than the weaker one.

Image signals are captured with rods and cones in the eye — the cones being responsible for colour.

“b” or “d”

The majority of cones, which come in red, green and blue variants, are found in a small spot at the centre of the cornea of the eye known as the fovea. But there is a small hole (about 0.1-0.15 millimetres in diameter) with no blue cones.

In the new study, Ropars and colleague Albert le Floch spotted a major difference between the arrangement of cones between the eyes of dyslexic and non-dyslexic people enrolled in an experiment.

In non-dyslexic people, the blue cone-free spot in one eye — the dominant one, was round and in the other eye unevenly shaped.

In dyslexic people, both eyes have the same, round spot, which translates into neither eye being dominant, they found.

“The lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities,” said the study authors.

Dyslexic people make so-called “mirror errors” in reading, for example confusing the letters “b” and “d”.

“For dyslexic students their two eyes are equivalent and their brain has to successively rely on the two slightly different versions of a given visual
scene,” the duo added.

The team used an LED lamp, flashing so fast that it is invisible to the naked eye, to “cancel” one of the images in the brains of dyslexic trial
participants while reading.

In initial experiments, dyslexic study participants called it the “magic lamp,” said Ropars, but further tests are required to confirm the technique really works.

About 700 million people in the world are known to suffer from dyslexia — about one in ten of the global population.

HEALTH

France brings in free contraception for all women aged 18-25

Free birth control for all women under 25 will be available in France from Saturday, expanding a scheme targeting under-18s to ensure young women don't stop taking contraception because they cannot afford it.

France brings in free contraception for all women aged 18-25
A doctor holds an interuterine contraceptive device (IUD) before inserting it in a patient. Photo: Adek Berry/AFP

The scheme, which could benefit three million women, covers the pill, IUDs, contraceptive patches and other methods composed of steroid hormones. Contraception for minors was already free in France.

Several European countries, including Belgium, Germany, the Netherlands and Norway, make contraception free for teens. Britain makes several forms of contraception free to all.

France announced the extension to women under 25 in September, saying surveys showed a decline in the use of contraception mainly for financial reasons.

The move is part of a series of measures taken by President Emmanuel Macron’s government to boost women’s rights and alleviate youth poverty. The free provision is supported by women’s groups including the association En Avant Tous.

“Between 18 and 25-years-old, women are very vulnerable because they lose a lot of rights compared to when they were minors and are very precarious economically,” spokeswoman Louise Delavier told AFP.

Leslie Fonquerne, an expert in gender issues, said there was more to be done.

“This measure in no way resolves the imbalance in the contraceptive burden between women and men,” the sociologist said.

In some developed countries, the free contraception won by women after decades of campaigning is coming under attack again from the religious right.

In the United States, former president Barack Obama’s signature health reform, known as Obamacare, gave most people with health insurance free access to birth control.

But his successor Donald Trump scrapped the measure, allowing employers to opt out of providing contraception coverage on religious grounds — a decision upheld by the Supreme Court in 2020.

Poland’s conservative government has also heavily restricted access to emergency contraception as part of its war on birth control.

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