Myopia: what it is, how you see and why it gets worse

The bus number you can only read when it is already at the stop. A friend’s face across the street that stays a blur until they come closer. And then, as soon as your gaze returns to the phone, everything is sharp again. If you are wondering what myopia is like, how the world looks, that is the whole answer.

The European Eye Epidemiology consortium (E3), which pooled the data of almost 62,000 adults in 15 population-based studies, estimated that about 30% of adults in Europe are myopic; in the 25–29 age group the share reaches 47%¹. Myopia can be corrected with glasses or contact lenses, but it is not only a matter of lenses: a very myopic eye is longer than normal, and over the years that length matters.

In this article

1. What myopia is
2. Myopia, how you see: sharp up close, blurred in the distance
3. Why myopia gets worse: the eye that lengthens
4. Why there are more and more myopic people
5. What risks myopia brings over the years
6. Frequently asked questions
7. Sources

What myopia is

The eye works like a camera. At the front there are two natural lenses, the cornea and the lens; at the back there is the retina, the membrane that turns light into signals for the brain. For a sharp image, light has to be focused exactly on the retina.

In the myopic eye the focus falls a little too soon. The reason may be an eye that is longer than it should be, in which case we speak of axial myopia, or a cornea or lens that is too ‘powerful’, in which case we speak of refractive myopia². In both cases a blurred image reaches the retina.

In 2019 the International Myopia Institute proposed common definitions for all studies: myopia is defined as −0.50 dioptres or below, high myopia as −6.00 dioptres or below, and pathological myopia when structural damage appears in the eye². The minus sign indicates the lens needed to correct the defect; how to read these numbers is explained in our article on dioptres and decimal acuity.

Myopia, how you see: sharp up close, blurred in the distance

A myopic eye has a ‘far point’ beyond which things begin to lose their outlines, and that point moves closer as the dioptres increase. Someone with one dioptre of myopia sees sharply up to about a metre; with two, up to about half a metre; with four, beyond 25 centimetres everything is already blurred. It is simple optics: the dioptre is the inverse of the distance in metres.

This is why mild myopia can go unnoticed for a while, whereas stronger myopia changes the day: not recognising people in the street, not reading signs, struggling with the board or with subtitles. Squinting helps a little, because the narrow slit between the eyelids lets through less blurred light, but it corrects nothing.

Why myopia gets worse: the eye that lengthens

In the first years of life a regulating system guides the growth of the eye towards the right focus, or towards slight long-sightedness. In many populations, however, myopia appears in later childhood and continues into adulthood: the eye keeps lengthening beyond what is needed³.

That is why children’s lenses change often: it is not the glasses’ fault, it is the eye that is growing, as we explain in the true-or-false on glasses. And stabilisation is not always a finish line: according to a 2025 review, progression in adulthood is also significant⁵.

Why there are more and more myopic people

In Europe myopia has become more common from one generation to the next. In the E3 consortium studies, the age-standardised prevalence rose from 17.8% of people born between 1910 and 1939 to 23.5% of those born between 1940 and 1979⁶. The same work found a clear link with education: 25.4% of those who had stopped at primary school were myopic, 29.1% of those who had finished secondary school and 36.6% of graduates; education, however, was not enough on its own to explain the increase⁶.

Worldwide the trend is more marked: a meta-analysis of 145 studies on 2.1 million people estimated that in 2000 22.9% of the world’s population was myopic, and projected that by 2050 almost half of humanity, 49.8%, will be, with 9.8% highly myopic⁷. Where this estimate comes from, and what the European data say, we described in the article on myopia in 2050.

As for the causes, a 2021 review by the International Myopia Institute distinguishes between strong and weak evidence. The link between education and myopia has been confirmed with genetic methods that help separate cause from mere association; the protective effect of time outdoors, by randomised trials. The link with near work is, by contrast, weak and inconsistent, although supported by a meta-analysis, and the one with screen time is, so far, weak and contradictory⁸. What this means for the youngest we explore in the article on myopia in children.

What risks myopia brings over the years

The length of the eye is not only an optical matter. A 2020 review with meta-analysis compared myopic with non-myopic people and found higher risks for several complications, increasing with the degree of myopia⁹.

Complication	Mild myopia	Moderate myopia	High myopia
Retinal detachment	about 3 times	about 9 times	about 13 times
Posterior subcapsular cataract	about 1.6 times	about 2.6 times	about 4.6 times
Open-angle glaucoma	about 1.6 times	about 2.9 times (single estimate)	about 2.9 times (single estimate)

The values in the table are odds ratios compared with people who are not myopic⁹. They need to be read carefully: they say by how much the risk rises, not how many people will actually become ill. The strongest link concerns myopic maculopathy, damage to the central part of the retina that, as the name says, is tied to myopia itself: the same analysis found associations much stronger than those in the table, and increasing with the dioptres⁹. The risk of losing vision, finally, rose with the length of the eye, with the degree of myopia and with age, and was particularly high in people with high myopia over 60⁹.

The authors’ message is not only about highly myopic people: even mild and moderate myopia carry considerable risks⁹. The 2025 review reaches the same conclusion⁵.

Frequently asked questions

Does myopia stop on its own?

It usually slows down and stabilises in adolescence: in the COMET study on average at around 15–16 years, but with large differences from one person to another⁴. In adulthood it can still change⁵.

Does wearing glasses make myopia increase?

No. Studies on children whose myopia was corrected less than needed found no slowing; a 2025 review concludes that undercorrection probably does not slow myopia⁵.

From how many dioptres is myopia called high?

International definitions set the threshold at −6.00 dioptres². In Europe about 2.7% of adults have high myopia¹.

Is myopia hereditary?

In part. In the COMET study, children with two myopic parents stabilised at about one dioptre more⁴. But the rise from one generation to the next indicates that environment and habits also matter, from education to time outdoors^6,8.

Myopia is the vision defect that weighs most among young Europeans¹, and in everyday life it is corrected with a lens. Studies of recent years have added a longer view: today’s dioptres also matter for tomorrow’s retina, which is why research looks more and more at the years in which the eye grows.