Myopia — also known as nearsightedness — is an eye condition characterized by blurry vision when looking at objects at a distance, but clear vision when looking at nearby objects. In myopia, light entering the eye is not refracted properly, causing the image to focus in front of the retina rather than directly on it, resulting in blurred vision.^[1]

Common signs and symptoms include blurry vision at a distance, headache, and eye pain.

Children often display other signs, such as bringing books unusually close to their faces to read and difficulty watching television from more than 3 feet (about 1 meter) away. These behaviors might suggest the need to consult a healthcare provider to be assessed for myopia or other vision problems.^[2]

Myopia is diagnosed when a person’s spherical equivalent (also known as a “prescription” for corrective lenses) is −0.5 diopters or lower. Diagnosis usually involves an eye examination by an optometrist or ophthalmologist, which may include assessments such as retinoscopy, auto-refractometer, corneal topography, and slit-lamp examination.^[2]

Myopia can be easily treated with corrective lenses, either through eyeglasses or contact lenses. There are also surgical treatments, such as laser vision correction (laser-assisted in situ keratomileusis, or LASIK) and intraocular lens implants. Some people may not be good candidates for surgical treatments, especially if their vision worsens every year or if they have a comorbid eye condition.^[1]

A potential pharmacological treatment is atropine eye drops for the prevention of myopia in children. However, this treatment may be accompanied by other unpleasant side effects, such as photophobia (fear/avoidance of light) and cycloplegia (the inability to focus on objects up close).^[3]

There is limited research on dietary supplements for treating myopia. There are some trials that have studied lutein,^[4] 7-methylxanthine (a caffeine metabolite),^[5] crocetin (a compound found in saffron),^[6] and anthocyanoside oligomers^[7] for treating myopia, but these supplements haven’t been thoroughly enough investigated to make any recommendations.

There is little to no research on the effect of diet on treating or preventing myopia. One cross-sectional study found that dietary patterns rich in whole foods such as meats, fish, dairy, eggs, legumes, fruits, vegetables, grains, and potatoes were associated with a lower risk of developing myopia in children from China.^[8] However, more high-quality research, including longitudinal and clinical trials, is needed to establish a better understanding of the relationship between diet and myopia.

There are some lens technologies that have shown some promise in slowing the progression of myopia, but more research is needed.^[9][10] It is also recommended for children to spend more time outdoors (around 2–3 hours per day), as there is evidence that spending more time outdoors can reduce the risk of myopia development in children.^[11]

Although myopia can have several causes, the most common cause of myopia is due to a front-to-back elongation of the eyeball, which is known as axial myopia. This elongation causes the focal point of the incoming light to sit in front of the retina rather than directly on it. This explains why myopia tends to worsen during the growing years, especially during childhood and adolescence, when the eyes are still developing and changing.^[1]