Are contact lens & glass prescriptions the same?

contact lens & glass

It’s easy to believe that your contact lens and glasses prescriptions are the same at first sight. After all, don’t they both correct the same visual issue? They resemble each other, yet they are not the same. While your prescriptions appear to be the same and correct your nearsightedness, farsightedness, or astigmatism, they are not interchangeable since they are personalized to the procedure employed.

Prescriptions for contact lenses and glasses have certain similarities, but they are not the same. They both fix refractive problems that make it difficult to see well. What is the definition of a refractive error? Refractive errors are vision abnormalities caused by the shape and capacity of your eye to bend light, resulting in hazy vision. Myopia (nearsightedness), hyperopia (farsightedness), and astigmatism are among them (when the curve of the eye is asymmetrical). Contact lenses and glasses may both correct refractive problems and restore eyesight. They do, however, function in quite distinct ways.

Because glasses and contact lenses are positioned differently in your eye, contact lens and glasses prescriptions are separate. Contact lenses lay directly on the eye’s surface, while glasses sit around 12 millimeters away. These 12 millimeters might make a huge difference in the prescriptions between the two. 

Furthermore, contact lens prescriptions require additional details that glasses do not. Among them are:

1) Lens Diameter – The lens diameter describes the lens’s size in relation to your eye. Soft contacts have a diameter range of 13.5 to 14.5 millimeters, whereas hard contacts have a diameter range of 8.5 to 9.5 millimeters. These sizes are not universal and necessitate a contact fitting examination.

2) Base Curve – The form of your cornea determines the base curve, which is the curvature of the rear lens. This curvature impacts how well the lens fits and how well it remains in position.

3) Lens Brand – Contact prescriptions, unlike reading glasses prescriptions, also include the lens brand. This is due to the fact that various brands employ different lens materials, which affect breathability. Without contacting an eye specialist, brands cannot be changed

4) Expiry Date – The expiration dates for contacts and glasses prescriptions are usually different. It’s likely that your contact prescription may expire before your glasses, so double-check!

There are a lot of discrepancies between these two prescriptions, as you can see! Because little differences can make a large impact, don’t try to predict, convert, or estimate your prescription based on another’s. Before buying new contacts or frames, be sure your optometrist has updated your prescription.

Many individuals wonder if their glasses prescription may be converted to contacts prescription. “No!” is the straightforward response. While there are online charts and conversions, a contact prescription requires an eye examination and contact lens fitting by a professional eye specialist. To establish the base curve, diameter, and lens material necessary for your specific eyes, you’ll need specialized knowledge.