Short-sightedness (myopia): children, eye tests and glasses, a review

Trouble reading the board at school can be a sign that a child is short-sighted. This article explains what myopia is, why it happens, how it is tested and managed, and how families can look after their eyes, using information from the NHS, the US National Eye Institute and MedlinePlus.

1. Introduction

Myopia, also called short-sightedness or nearsightedness, is a refractive error. A refractive error means the eye does not bend and focus light correctly, which causes blurry sight ^[3]. In myopia, light focuses in front of the retina, the light-sensitive layer at the back of the eye, instead of on it. Distant objects look blurry ^[4]. Other refractive errors are farsightedness, astigmatism (blurred or distorted sight at all distances) and presbyopia, which is difficulty seeing up close that usually begins around age 45 as the lens stiffens ^{[2, 3]}.

Myopia usually begins in childhood, between about ages 6 and 14 (the NHS says 6 to 13). The NHS says it can progress until the eye has stopped growing, usually around age 20, although adults can develop it too ^{[1, 4]}.

2. Causes and risk factors

Myopia happens when the eyeball grows too long from front to back, or when the cornea (the clear front surface of the eye) or the lens has an irregular shape ^{[3, 4]}. The NHS says it is not clear why short-sightedness happens ^[1]. Risk factors include:

• Having family members who are short-sighted, since it often runs in families ^{[1, 2, 4]}
• Starting in childhood. Children who spend more time outdoors are less likely to become nearsighted, though the reason is not known ^[4]. The NHS says outdoor time may help stop myopia getting worse ^[1].

3. Signs and symptoms

Signs described by the NHS and National Eye Institute include ^{[1, 2, 4]}:

• Difficulty seeing distant objects, such as a whiteboard
• Squinting and eye strain
• Sitting close to the television or holding devices near the face
• Headaches and frequent eye rubbing
• Needing a new prescription, if you already wear glasses or contact lenses ^{[2, 3]}

Mild myopia may cause no symptoms, so regular eye exams are advised ^{[2, 4]}. Parents can watch for these signs in children ^[1]. The National Eye Institute adds that headaches are less common than squinting and eye strain ^[4]. Because myopia can get worse until the eye stops growing, regular eye tests are useful ^{[1, 4]}.

4. Diagnosis and tests

An eye test is simple and painless. An optometrist asks you to read letters while different lenses are held in front of the eyes, and may use drops to look at the back of the eye ^{[1, 3, 4]}. MedlinePlus explains that eye care professionals include ophthalmologists, who are medical doctors, optometrists, who examine eyes and prescribe lenses, and opticians, who fit glasses and contact lenses ^[3]. If you need glasses, you get a prescription that you can take to any optician ^[1].

5. Treatment and management

Correction options are ^{[1, 2, 3]}:

• Glasses, which suit both children and adults
• Contact lenses, which suit adults and some children
• Laser eye surgery or lens surgery, which reshapes the cornea or changes the lens, for some adults. The NHS notes these are not available on its health service and can be costly ^[1].

The NHS says specialised lenses meant to slow the progress of myopia, known as myopia management, are not yet available on the NHS because more research is needed, and some opticians offer overnight orthokeratology lenses, which can improve vision during the day without glasses or contact lenses ^[1]. Speak to your eye professional about these options. The National Eye Institute describes glasses and contact lenses as the standard way to correct nearsightedness, and refractive surgery as an option mainly for adults ^{[2, 4]}. MedlinePlus says refractive errors are usually corrected with glasses or contact lenses, and a specialist can help you choose the best option for your eyes and way of life ^[3]. Young children with uncorrected short-sightedness may be more likely to develop a squint or a lazy eye ^[1].

6. Prevention and self-care

The sources do not describe a sure way to prevent myopia. These steps are suggested by them, and none is a promise that myopia will not develop ^{[1, 2, 4]}:

• Encourage children to spend time outdoors.
• Arrange regular eye tests, even if there are no complaints.
• Tell a doctor if vision gets worse or if there are problems with glasses or contact lenses ^[2].
• Encourage family members to get their eyes checked, since myopia often runs in families ^{[1, 2]}.

Under-16s qualify for free NHS eye tests and vouchers for glasses in the United Kingdom ^[1]. Elsewhere, ask your local eye professional how often your child should be tested.

7. When to see a doctor

See an optician soon if you or your child shows signs of short-sightedness, or if an eye test has not been done in two years ^[1]. See an eye professional if you have blurry vision even while wearing glasses, if your sight worsens, or if your glasses no longer seem right ^[2]. People with severe short-sightedness have a higher chance of other eye conditions, including glaucoma, cataracts, macular degeneration and retinal detachment, in which the retina pulls away from its normal position ^{[1, 4]}. Retinal detachment needs urgent treatment to prevent sight loss ^[1]. Any sudden change in your vision should be checked straight away.

In an emergency, call your local emergency number (112 in India, 911 in the United States).

8. Conclusion

Myopia is a common cause of blurry distance vision that often starts in childhood. Regular eye tests, properly prescribed glasses or lenses, and time outdoors are practical steps for families. Severe myopia needs closer monitoring for other eye problems. Your eye professional decides the best option.