Myopia (nearsightedness): what it is, signs and diagnosis

Myopia, or nearsightedness, is when you see clearly up close but distant objects are blurry. This type of vision is very common and is usually corrected with glasses or contact lenses. We explain what the eye looks like in myopia, which signs are noticeable without equipment, and what happens during a vision test.

Myopia: what it is and why the eye sees distant objects unclearly

The cornea and lens refract light so that it converges at a point on the retina. In myopia, this point falls in front of the retina — distant objects produce a blurred image. Rays from near objects are focused normally, which is why a book held in the hands can be read.

The most common cause is an elongated eyeball, so the retina ends up behind the focal plane. Less often, the cornea and lens refract rays more strongly than needed. Other variants include ciliary muscle spasm at a young age and lens displacement after injury. On a routine examination, the eye of a nearsighted person is most often structurally the same as an eye with normal vision.

Is nearsightedness a disease or a refractive feature

Formally, it is a refractive error, a type of ametropia, not damage to the tissues of the eye. There are four items on the list of common refractive errors: nearsightedness, farsightedness, astigmatism and presbyopia. The first three often begin in childhood or are present from birth, while presbyopia is an age-related matter, usually from age 45.

Myopia can be congenital or acquired, high (more than 6.0 diopters), axial, corneal, lenticular, night, progressive. False, spastic myopia is distinguished separately: it is associated with increased tone of the ciliary muscle and disappears when the tone normalizes.

Signs of nearsightedness

What it looks like in life: the blackboard in class "floats," the bus number can only be read up close, the phone ends up centimeters from the face on its own. Signs noticeable from the outside:

• difficulty reading words at a distance — for example, from the blackboard;
• wanting to sit closer to the TV or computer;
• it is more comfortable to hold a mobile phone and tablet close to the face;
• frequent headaches, rubbing the eyes, tension and fatigue.

Myopia usually begins in children aged 6–13 and may worsen while the eye grows — approximately until age 20. It also occurs in adults.

Why myopia occurs: causes and factors

The exact causes have not been reliably established. Nearsightedness often runs in families: if relatives wear glasses, the risk is higher. The role of prolonged near work — screens, studying, gadgets — and lack of time outdoors is discussed: children who spend more time outdoors have lower risks. There is a theory about vitamin D deficiency due to insufficient sun exposure.

Associated factors include endocrine changes during puberty, lack of calcium, zinc and selenium, hypovitaminosis, reduced immunity, and an unfavorable environmental situation. The scale of the phenomenon is notable: in some regions of Asia the prevalence of nearsightedness is 80–90%, in Seoul up to 96.5%; according to an estimate by the Brien Holden Vision Institute, by 2050 approximately 4758 million people will have myopic refraction.

Nearsightedness in adults and complications

Myopia also occurs in adults. With a high degree, the risks are higher: glaucoma, retinal detachment (urgent treatment is needed to avoid vision loss), cataract, and macular degeneration are more common. In young children with uncorrected nearsightedness, there is a higher likelihood of strabismus and "lazy eye," when the vision of one eye does not develop properly.

How myopia is diagnosed and when an ophthalmologist is needed

The diagnosis is made by a vision care specialist: an optometrist performs the examination, an ophthalmologist treats eye diseases, and an optician selects and adjusts glasses or lenses according to a prescription. At the appointment, they check how you see at different distances, with and without correction: you look at a light or read letters on a chart, while lenses are changed in front of your eyes. To assess eye health, drops that dilate the pupil may be instilled — this provides a better view of the fundus.

It makes sense to schedule a vision test if you notice signs of nearsightedness in yourself or your child, and also if you have not had a test for two years.

Nearsightedness itself is not a reason to call an ambulance. 103/112 — if retinal detachment is suspected: it requires urgent treatment to avoid vision loss.

This material is for reference and does not replace a doctor's consultation — if you have doubts about your vision, it is better to schedule an appointment.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer