A glasses prescription is a doctor's written order for corrective lenses, specifying the optical power needed to correct your vision. It includes numbers for each eye, often with abbreviations like OD, OS, and OU.
Your prescription details the degree of nearsightedness, farsightedness, astigmatism, or other vision issues. The numbers represent diopters, a unit measuring optical power. Positive numbers correct farsightedness; negative numbers correct nearsightedness.
For example, a prescription showing -2.50 for the right eye (OD) means moderate nearsightedness. A +1.00 for the left eye (OS) indicates mild farsightedness. If both eyes share the same value under OU, it applies to both.
Prescriptions typically include:
Many assume their prescription is universal, but glasses and contact lens prescriptions differ. Contacts require additional measurements like pupil distance and base curve. Your eye doctor provides separate prescriptions for each.
Another myth is that higher numbers mean worse vision. While higher absolute values indicate stronger prescriptions, they don't necessarily correlate with severity. A -8.00 prescription doesn't always mean worse vision than a -3.00 one-it depends on the individual's needs.
When ordering glasses, provide your full prescription, including PD (pupillary distance) and any special requirements. Double-check the numbers with your optometrist if anything seems unclear.