The Sphere (SPH) value on your prescription indicates the strength of the lens needed to correct your vision. A negative number means you are short-sighted, while a positive number means you are long-sighted. It is one of the key measurements that allows us to give you clear, comfortable sight, and it is usually recorded separately for each eye.
Understanding the numbers
The Sphere value is measured in units called dioptres. Generally speaking, the further the number is from zero, the stronger the correction that is required.
- A minus sign indicates short-sightedness (myopia)
- A plus sign indicates long-sightedness (hyperopia)
- A separate value is usually given for the right and left eye
How we can help
Your Sphere value is just one part of a full prescription, which we determine carefully and precisely during your eye examination. We are always happy to take the time to explain what your numbers mean and to make sure your lenses give you the clearest and most comfortable vision for your everyday needs.
If you would like to understand your prescription better, or to check that it is still up to date, we warmly invite you to book a comprehensive eye examination with our practice.