Myopia and pathological myopia
Myopia, also known as “being short sighted”, causes your vision to be blurry in the distance but clearer when looking at things up close.
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Myopia is a very common focusing problem, and for most people it can be easily corrected using glasses or contact lenses to make vision clear and crisp. Most people with myopia have healthy eyes.
Pathological myopia is different from simply being short sighted. Pathological myopia means that you are very short sighted and that this has caused degenerative changes to the back of your eye. Pathological myopia can cause a reduction in your sight that cannot be corrected with glasses or contact lenses.
This page contains a summary of our information on myopia and pathological myopia. To read our full information, download our factsheet:
What is myopia?
For vision to be clear, light entering your eye needs to be focused accurately on your retina. Light entering your eye is first focused by the cornea and then finely focused by the lens. Ideally, when light enters your eye, this focusing system should makes sure that when light enters your eye, it is sharply in focus as it reaches the retina. This will mean that you see everything in focus without any blurriness.
However, if someone has a focusing or “refractive” error, light is not focused correctly onto the back of the eye and vision is not clear.
In people with myopia, the light entering the eye comes to a focus point before it reaches your retina. This makes vision blurry and is caused by the eyeball being too long or the cornea (the clear window at the front of the eye) being more steeply curved.
People with myopia require a prescription for glasses or contact lenses with a minus lens power to correct their vision. This lens reduces the excessive bending of light by the eye, thereby focusing it onto the retina rather than infront of it, to produce a sharp clear image.
How is myopia graded?
Optometrists (also known as opticians) measure the focusing power of your eye in dioptres. This is a technical term for how strong a lens would have to be to correct the focusing of your eye and give you clear vision.
Myopia is written with a minus power on your glasses or contact lens prescription; for example, a prescription for three and a half dioptres of myopia would be written: -3.50 dioptres (D). The minus sign indicates that the lens is correcting for myopia. The higher the number, the more short sighted you are.
- Mild myopia includes powers up to -3.00 dioptres (D).
- Moderate myopia, a power of -3.00D to -6.00D.
- High myopia is usually a power over -6.00D.
Most people with myopia of less than -6.00D don’t develop any further problems. This is sometimes known as simple myopia, meaning that your eyes are healthy and that the blurriness that your myopia causes is easily corrected for with glasses or contact lenses.
If you have myopia higher than -6.00D, you may be at greater risk of developing the following eye conditions:
However, not everyone with myopia above -6.00D will develop other eye conditions, and for most people their eyes will be healthy.
If you’ve been diagnosed with pathological or degenerative myopia, you have very high myopia, and your eye also shows degenerative changes affecting the back of the eye (the retina).
How does pathological myopia affect the retina?
- Retinal atrophy – these are areas where your retina has become very thin and is no longer working.
- Lattice degeneration – a type of retinal thinning at the far edges of your retina.
- Lacquer cracks – breaks that occur in the membrane (Bruch’s membrane) between the retina and its underlying blood supply (the choroid layer).
- New blood vessels (myopic choroidal neovascularisation) – new leaky blood vessels can grow from the blood supply underneath the retina (from the choroid layer), through lacquer cracks or areas of atrophy onto the retina.
- Myopic macular degeneration – these degenerative changes can develop at the macula (the central part of the retina). Myopic macular degeneration is also known as myopic maculopathy and can affect your central detailed vision.
- Foster Fuchs spot – myopic choroidal neovascularisation can lead to scarring at the macula, known as a Foster Fuchs spot. This scarring can cause a blank or missing patch in your central vision.
What treatments are there for pathological myopia?
The type of treatment you may need will depend upon the degenerative change that has developed. Unfortunately, not all the changes that happen in pathological myopia, such as retinal atrophy and lacquer cracks, can be treated.
If you start to develop new blood vessels at the macula, this can be treated with anti-vascular endothelial growth factor (anti-VEGF) treatment. Anti-VEGF medications work by reducing the growth of new, leaky blood vessels and the oedema (swelling) they may cause. This treatment can reduce the risk of scarring and damage to the retina caused by these new vessels, which in turn can help to avoid further deterioration in sight.
Is there anything I can do to prevent pathological myopia?
If you already have high myopia, there are no treatments available to stop your eye from developing the complications of high or pathological myopia. This is because it’s not possible to control the growth of your eye. There’s currently no evidence to suggest that diet, vitamins, or supplements can affect your chances of developing pathological myopia or make it worse.
Currently treatment is aimed at improving your vision and to treat any complications if they happen. You will be monitored regularly by your optometrist or ophthalmologist (hospital eye doctor) who will check the health of your eyes. It’s important to have your eyes checked by your optometrist or ophthalmologist as soon as possible if you notice any changes to your vision or any new symptoms.
How can I see better?
Most people who have myopia don’t have any complications and will only ever need glasses or contact lenses to make their vision sharper. If your prescription is over -10.00D, then you would be entitled to a NHS complex lens voucher to use towards the cost of your glasses or contact lenses. Your optician would be able to tell you how much this voucher is worth and if your prescription would entitle you to a NHS complex lens voucher.
The higher your level of myopia is, the higher the risk of developing eye conditions associated with myopia and pathological myopia. If your retina has been damaged, then your vision may need more than glasses to help you see well.
Low vision assessments and making the most of your sight
A low vision assessment can explore how to make the most of your sight. This may mean making things bigger, using brighter lighting, or using colour to make things easier to see. Your GP, optometrist or ophthalmologist can refer you to your local low vision service for an assessment. You can also find out tips for making the most of your sight by downloading our booklet:
Many people with pathological myopia find that they are sensitive to light, known as photophobia. You may find bright light uncomfortable, or you find it difficult to adapt to changing levels of lighting. Using sunglasses, tinted lenses and sunshields can all help to reduce the discomfort and glare you may experience in everyday living.
Find more information about light sensitivity.
If you have pathological myopia or an eye condition caused by high myopia, you may have sight problems which cannot be corrected with glasses or contact lenses. If this is the case, you are required by law to tell the Driver and Vehicle Licensing Authority (DVLA) if the changes are affecting both your eyes. You may be able to continue driving if your sight meets the DVLA visual standards. Your optometrist or ophthalmologist will be able to tell you if your vision meets the DVLA standard or if you need to tell the DVLA about your sight problems.
Page last reviewed: Oct. 13, 2022
Next review due: Jan. 31, 2023