Eye health resource
The Link Between Myopia, Cataracts, & Glaucoma
Higher levels of myopia are associated with greater risk of several eye-health problems, including glaucoma, cataract, retinal detachment, and myopic macular changes.
Reviewed for accuracy by Justin Bazan, OD on .
Myopia—also called nearsightedness—is usually discussed as a focusing problem: distance vision is blurry because light comes to focus in front of the retina rather than directly on it. But myopia can also matter for long-term eye health.
As the degree of myopia increases, the risk of several eye conditions also rises. The association is especially important in high myopia, where elongation of the eye can affect the retina, choroid, optic nerve, and other structures.
What Is High Myopia?
The International Myopia Institute (IMI) uses a spherical-equivalent refractive error of -6.00 diopters or more myopic as a standardized research definition of high myopia. That threshold is useful for consistency, but it is not a magic line where risk suddenly begins.
Refractive error alone also does not determine whether someone is legally blind. Legal blindness is based on best-corrected visual acuity and/or visual field criteria, not simply on how many diopters of myopia appear in a prescription.
Many people with high prescriptions see very well with appropriate glasses or contact lenses. The reason high myopia deserves extra attention is the greater probability of structural eye changes and associated disease over a lifetime.
High Myopia Is Not the Same as Pathologic Myopia
High myopia describes the amount of refractive error. Pathologic myopia refers to structural changes related to excessive axial elongation—such as posterior staphyloma, myopic maculopathy, or other posterior-segment changes—that can reduce best-corrected vision.
The two overlap, but they are not interchangeable. A person can have high myopia without pathologic myopic changes, and pathologic changes cannot be diagnosed from the spectacle prescription alone.
Myopia and Glaucoma
Myopia, particularly higher myopia, is associated with an increased risk of glaucoma and glaucoma-like optic-nerve damage. Glaucoma is a group of diseases that damage the optic nerve. Elevated eye pressure is an important risk factor, but glaucoma can occur even when measured pressure is within a statistically normal range.
High myopia can also make the optic nerve more difficult to interpret because the shape of the eye and optic disc may differ from a non-myopic eye. That makes careful examination, appropriate imaging, pressure measurement, visual-field testing when indicated, and follow-up over time especially useful.
Park Slope Eye uses tools including medical eye examination and OCT imaging when clinically appropriate, but no single scan or pressure reading diagnoses glaucoma by itself.
Myopia and Cataracts
A cataract is clouding of the eye's natural lens. Cataracts become more common with age, but myopia—especially higher myopia—has been associated with an increased risk of certain cataract types and with cataract surgery at a younger age in some populations.
That does not mean everyone with myopia will develop an early cataract. Age, genetics, diabetes, medications, smoking, UV exposure, trauma, and other factors also influence cataract risk.
Myopic Maculopathy
In pathologic myopia, excessive elongation of the eye can mechanically stretch and remodel tissues at the back of the eye. These structural changes can affect the retina, retinal pigment epithelium, choroid, and Bruch's membrane and may lead to myopic maculopathy.
Possible findings include areas of chorioretinal atrophy, lacquer cracks, posterior staphyloma, and myopic choroidal neovascularization (abnormal new blood vessels beneath the retina). These changes are related to the structure of the elongated eye—not because an image “overshoots” the macula or because retinal cells weaken from disuse.
New distortion, a new central blind or blurry spot, or a sudden change in central vision deserves prompt evaluation.
Myopia and Retinal Detachment
Higher myopia is also associated with an increased risk of retinal tears and retinal detachment because an elongated eye can be accompanied by peripheral retinal thinning and vitreoretinal changes.
New flashes of light, a sudden shower of floaters, or a curtain/shadow in the vision can be warning signs of a retinal tear or detachment and require urgent evaluation.
Can Myopia Management Reduce These Risks?
In children with progressing myopia, the purpose of myopia management is to slow the rate of myopia progression and, when possible, slow excessive axial elongation. It is not simply a way to reduce symptoms, and no treatment can guarantee that future eye disease will be prevented.
Depending on the child and family, Park Slope Eye may discuss options including:
- Ortho-K
- Low-dose atropine
- Appropriate soft multifocal/myopia-control contact lenses
Ortho-K is one myopia-management option, not the only one. The best approach depends on prescription, progression, age, eye health, lifestyle, and the family's ability to follow treatment and follow-up recommendations.
What Should Adults With High Myopia Do?
Adults with high myopia do not need to assume that vision loss is inevitable. The practical goal is regular eye-health monitoring and prompt attention to new symptoms.
A comprehensive eye exam can assess vision and eye health, while additional testing may be recommended based on the optic nerve, retina, symptoms, medical history, and other findings. Dilation may still be recommended when it is clinically necessary, even when retinal imaging has been performed.
If you have a high prescription or a family history of glaucoma, retinal disease, or other eye conditions, ask your eye doctor what follow-up schedule is appropriate for you.
Originally published . Substantially updated .