You will receive a printout of your prescription at the end of the eye exam in our office. It can be confusing to try to understand your glasses prescription. The printout may contain various abbreviations and numbers. To help you better understand your prescription, we're going to discuss some basic prescription terms in this blog.
What does Your Glasses Prescription Mean?
- The OD refers to your right eye's prescription
- The OS is the prescription for the left eye
- OU refers to both eyes together
- Under the sphere (SPH) column, you will find your overall lens prescription. Distance corrections for farsightedness (hyperopia) are indicated by a plus ( + ), while corrections for nearsightedness (myopia) are indicated by a minus ( - ).
- Another part of your prescription is the cylinder (CYL) which refers to how much power you need to correct the curvature of your eye, which is commonly prescribed for patients with astigmatism.
- Axis refers to the direction in which astigmatism needs to be corrected.
- An add column might be on your prescription if you are over 40 years old and need glasses to read or do near work. It is possible to get single vision glasses that are only for distance or only for reading or you can get bifocal or multifocal glasses if you have been prescribed add (for patients with presbyopia).
Are Glasses and Contact Lens Prescriptions the Same?
Generally, contact lenses have different prescriptions than glasses because they sit on the eye, so the distance is different. There might be different powers for astigmatism and spherical powers in your contact lens prescription, in addition to the base curves that describe the curvature of the lenses, as each pair has a different base curve. Another component of a contact lens prescription is the diameter, which indicates their size. Also specified on the prescription is the brand of contact lenses, what type should be worn, and whether they should be changed daily, every two weeks, or monthly.
