Is -3.00 Myopia Bad?
Short answer: −3.00D is the most common prescription in myopic adults worldwide. It's meaningful — you need correction for any distance activity — but structural risk is still substantially lower than high myopia (−6.00D and above). Monitor annually with a dilated exam.
Where -3.00 sits in the risk spectrum
Myopia severity is better understood through axial length (the physical length of the eye in millimetres) than through the diopter number alone. Two people can have the same prescription from different amounts of axial elongation — and axial length is what determines long-term structural risk, not the diopter number itself.
| Prescription | Approx. axial length | Structural risk category |
|---|---|---|
| -1.00D | ~24.2mm | Low |
| -2.00D | ~24.7mm | Low–Moderate |
| -3.00D | ~25.2mm | Moderate |
| -4.00D | ~25.8mm | Moderate–High |
| -5.00D | ~26.1mm | High |
| -6.00D | ~26.6mm | High (IMI threshold) |
| -8.00D | ~27.5mm | Very High |
| -10.00D | ~29.0mm | Extreme |
AL–refraction mapping is approximate (±2–3D individual variation). Based on Flitcroft 2012; Tideman et al. 2016. Your row is highlighted.
Clinical perspective
At −3.00D, axial length is approximately 25.0–25.5mm — still below the structural threshold. Risk of retinal detachment and maculopathy rises progressively with axial length, becoming clinically significant above 26mm. Patients at −3.00D are not in a high-risk zone but should maintain annual dilated examinations.
For parents: what this means for a child at -3.00
A child at −3.00D is approaching the range where cumulative lifetime structural risk becomes a genuine concern. Whether they reach −5.00D or −7.00D by adulthood depends heavily on what happens in the next few years of childhood. Early intervention now is more effective than later.
What to do at -3.00
Children at −3.00D with ongoing progression are strong candidates for myopia management. The earlier treatment starts, the more structural elongation is prevented.
Calculate your exact progression rate
Enter age and two axial length measurements. Get progression rate, AL percentile, and projected prescription at age 18 — with and without treatment.
Check progression now →This page is for educational purposes and does not constitute medical advice. Diopter-to-axial-length conversions are approximations (±2–3D individual variation). MyopiaTracker is a decision-support tool — not a diagnostic device. Consult a qualified optometrist or ophthalmologist for personalised advice.