MyKidsVision

The risks of high myopia

Key points

  • High myopia is defined as an individual has at least -5.00 diopters (D) of myopia
  • It is strongly associated with an increased risk of glaucoma, cataract, retinal detachment and myopic maculopathy
  • high myopia can affect quality of life and increase the cost of living

In this article:

High myopia is strongly associated with an increased risk of sight-threatening eye disease. It has also been shown to negatively affect vision-related quality of life.

What is high myopia?

High myopia is defined as an individual has at least -5.00 diopters (D) of myopia in either eye by the World Organisation Health (WHO).1 Globally, the number of individuals with myopia is increasing at an alarming rate. By the year 2050, it is estimated that half of the world's population will have myopia, and about 10% of those will develop high myopia.2

How does high myopia impact eye health?

High myopia occurs when the eye ball has grown excessively long (more than 26mm). Due to the extensive growth of eye, it creates additional stress on the eyeball, which increases the risk of sight-threatening eye disease.3

Eye conditions associated with high myopia

Glaucoma

Glaucoma is a progressive condition whereby the optic nerve is damaged over time from increased eye pressure. While the exact cause is still not fully understood, studies suggest that excessive eye growth contributes to glaucoma development. This can lead to permanent vision loss. Higher degrees of myopia are more associated with glaucoma, as for every -1.00D increase in myopia, the risk of glaucoma increases by approximately 20%.4

Cataract

Cataract is the clouding (opacification) of the eye’s lens that can cause blurry or foggy vision. Individuals with high myopia tend to develop cataracts about 10 years earlier than those without myopia.5 At the same time, those with high myopia are more prone to complications – such as retinal detachment, following cataract surgery (to treat cataracts).6

Retinal detachment

Retinal detachment is a serious eye condition where the retina (light-sensing tissue) separates from the back of the eye, causing sudden vision loss. Individuals with high myopia are more prone to developing retinal detachment, as their excessively long eyeball causes the retina to stretch under strain.2

Myopic maculopathy

Myopic maculopathy is a type of macular degeneration, where an elongated and stretched eyeball causes irreversible damage to the area at the back of the eye responsible for central vision (the macula).2

How high myopia impacts everyday life

Individuals with high myopia must rely on glasses or contact lenses to see clearly for everyday tasks. Without wearing glasses or contact lenses to correct their vision, quality of life becomes significantly reduced. For example, uncorrected myopia of -4.00D is considered a level of visual impairment that qualifies as legal blindness.

Yet, overcoming the challenges of wearing corrective lenses is not so simple. Even though refractive surgery (like LASIK) can be performed to correct vision, surgical outcomes tend to be slightly less favourable in high myopia compared to lower degrees of myopia.7 Laser eye surgery also does not make an eye less prone to developing eye disease either, as the operation does not correct the elongated shape of the eye ball.

The cost of managing high myopia can also be significant.

  • Eyeglasses for high myopia are often more expensive because they require high-index lenses, which are thinner, lighter, and more cosmetically appealing than standard lenses. Standard lenses are not suitable for high prescriptions.
  • Ongoing eye care costs tend to be higher too, as people with high myopia need regular checkups to monitor their eye health.
  • Treatment costs for managing myopia-related eye conditions can add further burden —often requiring surgery, advanced imaging, or long-term follow-up.

How to minimize the risks of high myopia

If your child does not have myopia:

  • School age children developing normally should have an eye test every 1 to 2 years, unless suggested otherwise by your optometrist or eye doctor
  • Ensure they spend at least 2 hours outdoors every day
  • Follow the 20-20-20 rule: Every 20 minutes of near work (like reading or screen time), look at something 20 feet away for 20 seconds

If your child has low, moderate or high myopia :

  • Start myopia control treatment early, to reduce the worsening of myopia
  • Continue regular eye examinations with your optometrist or eye doctor, ideally at least every 6 months
  • Make sure they get at least 2 hours of outdoor time daily
  • Apply the 20-20 rule, the two-hour rule and the elbow rule to manage near work and screen time
Information

All children with myopia need regular eye health checks of the front and back of the eyes. This is even more crucial in children with high myopia, where a yearly detailed examination of the retina (light-sensitive layer at the back of the eye) is recommended by experts.8

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