Contact Lens Powers Explained: Nearsighted, Farsighted, Astigmatism and Presbyopia
The power of your contact lenses decides how well they correct your vision, and getting it right is what makes the difference between sharp, comfortable wear and a long day of squinting. Whether you are nearsighted, farsighted, have astigmatism or need reading correction, this guide walks through the ranges we carry and what to weigh when choosing.
Nearsighted powers
Nearsightedness is the most common prescription. It is written as a negative number — -1.00 is what an optician in Hong Kong would call 100 degrees, and -10.50 is 1050 degrees. Prescriptions fall roughly into three bands:
-
Low: -0.50D to -3.00D
Comfortable for everyday wear. At this end you can choose mostly on comfort and breathability. -
Moderate: -3.25D to -6.00D
A mid-range water content tends to hold up best over a long day. -
High: -6.25D and above, up to -20.00D or beyond
At high powers, look for a highly oxygen-permeable material to keep the strain on your eyes down, and keep up with regular eye examinations.
Farsighted powers
Farsighted prescriptions are written as a positive number — +1.00 is 100 degrees — and correct blurring at close range. The range generally runs from +0.50D to +15.00D.
What to weigh:
- Comfort and breathability matter most if you wear lenses for long stretches.
- Some farsighted lenses are thicker; a thinner design is worth looking for.
Astigmatism
Lenses for astigmatism have to correct two things at once: the cylinder and the axis. Cylinder usually starts at -0.75D and goes up to -2.75D, depending on the product.
What to weigh:
- Check that the product carries both your cylinder and your axis.
- Higher astigmatism (around -2.75D and above) may need a specially designed lens to correct reliably and stay stable on the eye.
- Order from your eye examination report, and confirm the fit with your optometrist.
Presbyopia
Presbyopia generally starts to affect people over 40, and the add power runs from +1.00D to +2.50D, depending on the product. Multifocal lenses correct near and distance vision at the same time.
What to weigh:
- Pick the multifocal design that suits your add power and your day — bifocal or progressive.
- First-time multifocal wearers usually need an adjustment period. Start with short wear and build up.
For which multifocal lenses are actually available, and how they compare on replacement cycle, material and prescription coverage, see our multifocal contact lens buyer's guide.
Power ranges at a glance
The table below summarises the ranges and the main thing to weigh for each:
| Type | Power range | Highest example | What to weigh |
|---|---|---|---|
| Nearsighted | -0.50D to -20.00D | -20.00D | At high powers, choose a highly oxygen-permeable material. |
| Farsighted | +0.50D to +15.00D | +15.00D | Comfort and breathability. |
| Astigmatism | -0.75D to -2.75D | -2.75D | Confirm the product carries your axis. |
| Presbyopia | +1.00D to +2.50D | +2.50D | Consider a multifocal design for mixed distances. |
Frequently asked questions
Q1: Is my contact lens power the same as my glasses power?
A1: Not exactly. A contact lens sits on the eye, so the power can differ slightly from your glasses, and the gap widens at higher prescriptions. Ask your optometrist for a contact lens prescription rather than converting one yourself.
Q2: How do I know my power is right?
A2: If your vision is sharp and the lenses feel comfortable, the power is probably correct. Blurring, headaches or tired eyes are a sign to have your eyes re-examined and the power adjusted.
Q3: Are high-power lenses thick?
A3: Modern manufacturing keeps even high-power lenses thin, though they can still be slightly thicker. A higher refractive index material helps.
Q4: How do cylinder and axis affect my choice?
A4: A lens for astigmatism has to match both your cylinder and your axis, or vision can blur and the lens can rotate on the eye. Order from your eye examination report and confirm the product carries your axis.
In closing
Choosing the right power is the first step to seeing clearly in contact lenses. Whether you are nearsighted, farsighted, have astigmatism or need reading correction, knowing the range and matching it to how you actually live matters. Have your eyes examined regularly and ask your optometrist for advice specific to you — we hope this guide leaves you more confident about what to order.