What Does -9.75 (Minus 9.75) Eye Power Mean?
Quick answer. -9.75 means you are nearsighted (high myopia). Light focuses in front of the retina, so distant things look blurry while close-up vision stays clear. Without glasses you see clearly up to about 10 cm / 4 inches. Not safely – this level usually does not meet the legal driving standard uncorrected, so wear your glasses or contacts to drive.
High myopia (above -6.00)
Where this sits on the myopia/hyperopia scale
What you can and can't see
Can see clearly up to
10 cm / 4 inches
Can you drive with this prescription?
You'll typically want correction for:
- driving
- nearly all distance vision
- wearing correction full-time is likely
Can you drive with this prescription?
Not safely – this level usually does not meet the legal driving standard uncorrected, so wear your glasses or contacts to drive.
Contact lens power
Because -9.75 is stronger than +/-4.00, the contact-lens equivalent is vertex-adjusted to about -8.75.
Check another value
Enter any sphere (SPH) power to open its page:
What SPH, CYL and AXIS mean
- SPH (Sphere)
- The main lens power that corrects nearsightedness (minus) or farsightedness (plus). This is the number this page decodes.
- CYL (Cylinder)
- Extra power that corrects astigmatism. A blank or 0 means none.
- AXIS
- The angle (1-180 deg) where the cylinder power is placed. Only relevant if you have a CYL value.
- OD / OS
- OD = right eye, OS = left eye. Each eye can have a different SPH.
Why this matters
Knowing what -9.75 means helps you understand your own eyes, compare glasses and contact-lens options, and ask better questions at your next eye test. The number itself is just a measure of focusing power – it does not describe eye health, which only an exam can assess.
Frequently asked questions
Is -9.75 a strong eye prescription?
-9.75 falls in the high range: High myopia (above -6.00). -9.75 prescriptions are high on the overall scale.
Can I drive with -9.75?
Not safely – this level usually does not meet the legal driving standard uncorrected, so wear your glasses or contacts to drive.
Is -9.75 myopia or hyperopia?
-9.75 is high myopia. The minus sign tells you the type.
Is the contact lens power the same as -9.75?
No. Above +/-4.00 the lens sits closer to the eye, so the contact-lens equivalent is about -8.75.
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Open the full Eye Prescription Decoder
This tool explains what your numbers mean in plain language. It is educational only and not a substitute for an eye exam. Always see a qualified optometrist or ophthalmologist for diagnosis and a prescription.