With changing lifestyles, more and more people develop myopia during their teenage years. However, once myopia exceeds 600 diopters, it’s no longer just about blurry vision—it may bring a range of serious eye health risks. Aye specialists define "high myopia" as having a prescription of 600 diopters or more. Beyond this threshold, significant changes occur in the eye’s structure, and the risk to eye health rises sharply.

Why is 600 Diopters an Important Threshold?

The normal axial length of an adult’s eye is about 24 millimeters, while in myopic eyes, the axial length is often longer. For every 300 diopters increase in myopia, the eye’s axial length typically elongates by about 1 millimeter. When myopia reaches 600 diopters, the axial length usually exceeds 26 millimeters, causing obvious deformation of the eyeball. This elongation not only results in blurry vision but also places increasing stress on the retina and choroid, key eye tissues. Such pressure can lead to damage and elevate the risk of blinding eye diseases.

Studies show that people with high myopia over 600 diopters have an 8 to 10 times higher risk of retinal detachment compared to the general population, a 14 times greater risk of glaucoma, and a threefold increase in cataract incidence. In other words, 600 diopters is not only a turning point for vision but also a critical warning line for eye health risks.

Eye Changes After Reaching 600 Diopters Myopia:

1. Retinal Issues: Detachment, Tears, Bleeding

If vitreous fluid leaks through these tears, retinal detachment can occur. Patients may suddenly see shadows or flashes of light. Without prompt surgery, permanent vision loss can happen within 48 hours.

2. Macular Degeneration: Damage to the Vision Core

The macula is the most sensitive part of the retina responsible for sharp central vision. In high myopia, elongation causes chronic oxygen deficiency in this area, leading to bleeding, tears, and other lesions. This results in blurred central vision, distortion of straight lines, and even loss of reading ability.

3. Posterior Staphyloma: Eyeball Structural Collapse

Long-term eye expansion can cause a bulging “staphyloma” at the back of the eyeball. This leads to choroidal atrophy and abnormal growth of new blood vessels, which may cause bleeding at the back of the eye and rapid vision decline. Such conditions are usually irreversible and require surgery to slow progression.

4. The Hidden Danger of High Myopia Complications

High myopia is dangerous partly because its complications develop silently. Early symptoms like mild floaters or slight blurriness are often overlooked until serious damage occurs. Certain intense activities such as bungee jumping, diving, or heavy weightlifting can trigger retinal tears or sudden spikes in eye pressure, potentially causing abrupt vision loss. For high myopia patients, eye health can be like a ticking time bomb ready to “explode” unexpectedly.

How to Prevent and Manage High Myopia?

1. Early Intervention

Start young. The key to fighting myopia is early control, screening, and prevention. For teenagers with myopia under 600 diopters, daily outdoor activity for at least two hours is recommended to use natural light to slow axial elongation. Adhere to the "20-20-20" guideline: after every 20 minutes of screen use, focus on an object 20 feet away for a minimum of 20 seconds to alleviate eye strain.

2. Medical Treatments

For children and teens, orthokeratology lenses (OK lenses) and low-dose atropine eye drops have proven effective at slowing myopia progression. For those with myopia at or above 600 diopters, regular fundus examinations, OCT scans, and axial length measurements are critical. Additionally, patients with diabetes or hypertension should closely monitor eye pressure and vascular health to detect and address problems early.

3. Lifestyle Adjustments

Avoid strenuous activities that cause strong eye jolts, such as diving or bungee jumping. During workouts, avoid holding breath or exerting excessive pressure that can raise eye pressure. Remove contact lenses during naps, and avoid using phones in complete darkness at night to prevent worsening vision.

4. Regular Eye Checkups for Early Detection and Treatment

Highly myopic patients should have annual eye health exams, including fundus exams, intraocular pressure measurement, and OCT scans. This helps detect retinal, macular, or pressure abnormalities early, enabling timely treatment to prevent progression.

Research shows that controlling myopia under 600 diopters before age 18 significantly reduces future risks of cataracts and retinal detachment.

Summary

A myopia of 600 diopters is a crucial warning sign that the eye’s structure has undergone serious changes, greatly increasing health risks. To maintain healthy vision, prevention should start early with scientific eye care, regular checkups, and avoidance of high-risk behaviors.