Myopia, known as ‘short-sightedness’ or ‘near-sightedness’, means you can see close-up things more clearly, but objects further away appear blurry. This eye condition is very common, and it’s easily corrected by wearing contact lenses or glasses for most people.
Myopia often starts in childhood, getting progressively worse until early adulthood, when eyesight tends to stabilise. Symptoms include blurred vision, finding distant objects hard to see clearly, as well as squinting, headaches, and eye strain.
Myopia varies in severity. Some people have high myopia, which can be associated with other eye conditions. Degenerative myopia is when the condition causes changes to the retina at the back of the eye. This is much less common than mild short-sightedness.
Symptoms of untreated myopia include:
- Blurred distance vision (close objects look clearer, but those further away are blurry)
- Eye rubbing
- Excessive blinking
Myopia often starts in childhood - from as early as six years - so it's a good idea to look out for symptoms such as these in your child. Children can’t always describe problems with their sight for themselves. One common sign to watch out for is that children who are short-sighted often complain of difficulty reading the board or screen during lessons at school.
Types of myopia
Myopia is a type of refractive error - light rays travelling through the eyeball to the back of the eye don't bend correctly. It is typically caused by the eyeball being too long or the cornea becoming too curved. Light travelling through the eye doesn't focus properly on the light-sensitive retina, leading to short-sightedness.
The severity of myopia varies, as does its impact on the eye and vision. Opticians measure the strength of myopia in ‘dioptres’ (D) with a negative number indicating short-sightedness.
How to treat myopia
There are several options for treating myopia. These can include:
- Prescription glasses or contact lenses
- Laser eye surgery
- Lens implant surgery
Myopia can have genetic factors and often runs in families, so you’re more likely to develop it if one or both of your parents are short-sighted.
Research has found that environmental factors are also thought to play a role, such as spending a lot of time indoors or doing near work (for example, reading, writing, and using computers) (Source: Nature).
Sometimes other conditions in adults can cause or increase the risk of myopia, such as diabetes and cataracts.
Causes of myopia in children
Research suggests that children who don't spend enough time outdoors and do a lot of reading or using screens are at greater risk of myopia.
It’s a good idea to encourage children to get outdoors every day and have regular screen breaks when possible.
Your optician can diagnose myopia at a routine eye examination. The key measure opticians use to describe myopia is ‘dioptres’.
Dioptres measure how well your eyes focus and how strong a corrective lens you need. Opticians grade the strength of myopia as:
- Down to -3D is classed as mild myopia
- Between -3D and -6D is moderate myopia
- Stronger than -6D is high myopia
Mild to moderate myopia is not usually associated with developing other eye conditions or vision problems and can be corrected by glasses or contact lenses.
Degenerative myopia will be diagnosed when someone with high myopia also experiences degenerative changes at the back of the eye, in addition to their significant short-sightedness.
When to get medical advice
If you have myopia, you should have eye tests at least every two years to check for changes to your prescription and monitor your general eye health. Eye drops can also help if your eyes feel dry or sore.
If you have high or pathological myopia, it’s even more important to have regular eye tests and get help quickly if you notice changes to your sight.
If short-sightedness goes untreated in children, other problems can develop such as a squint (although this is rare). If you have any concerns about your child’s sight, take them to see an optician.
Living with myopia
Most people with myopia can have their vision corrected by wearing contact lenses or prescription glasses. Having regular eye exams will help keep on top of the condition. Some people opt to pay for laser eye surgery so that they don't have to wear lenses.
If you have high or pathological myopia, you might be eligible for some extra support, for example, help with the cost of prescriptions. Find out more about living with myopia.
Frequently asked questions
Medically reviewed by: The Royal College of Ophthalmologists on 18/10/2022
Edited by: Nick Astbury FRCS FRCOphth FRCP
Clinical Associate Professor
The Royal College of Ophthalmologists champions excellence in the practice of ophthalmology and is the only professional membership body for medically qualified ophthalmologists. The RCOphth is unable to offer direct advice to patients. If you’re concerned about the health of your eyes, you should seek medical advice from your GP, optometrist or ophthalmologist.