How should I get my contact lens prescription?
Contact lens prescriptions are very different from those of frames. But do you know exactly what is different? The conversion of the prescriptions between them is related to whether or not your eyes will get tired. Therefore, this article will explain to you how they are related to each other.
During the eye examination, the optometry frame is worn on the nose, exactly as you would normally wear glasses. There is a small distance between the cornea and the frame, which is different from wearing contact lenses, so the prescription is only suitable for use with glasses. Contact lenses fit snugly on the cornea, so we need to convert the prescription to fit your needs.
Contact lens prescription conversion formula
How should I convert? There is a formula to calculate.
Contact lens prescription = number of eyeglasses / [ 1 – ( distance from corneal frame * number of eyeglasses ) ]
As a small example:
- Glasses – 500 degrees
- Contact lens prescription = -5.00 / [ 1 – ( 0.012 * -5.00 ) ]
- Calculation result = 4.72
- So the contact lens prescription is -475 degrees
This is the reason why we often talk about the need to reduce the prescription of contact lenses. However, not all glasses need to be converted. If the myopia is less than -400 degrees, you can generally get away with not converting or lightening the prescription.
How should I convert my contact lens astigmatism?
Contact lenses can generally correct minor astigmatism. If the astigmatism is -0.25 or -0.50, you do not need to wear contact lenses with astigmatism, but if the astigmatism is more than -0.75 degrees, it is recommended to purchase contact lenses with astigmatism.
Astigmatism can be converted down to a shallow level to choose right astigmatism, for example, the glasses astigmatism -1.25 degrees, down to a shallow level to find the closest astigmatism of the brand of contact lenses, the following figure for example, the astigmatism is -0.75 degrees.
To make the conversion quicker, you can follow the conversion table below to find the contact lens prescription you need according to your own glasses. Because different brands of contact lenses have different combinations of prescriptions, the prescription conversion table is for reference only.
Finally, if you need custom contact lenses with a prescription, welcome to consult with freshlady wholesaler, which has a professional factory and sales team that can provide you with quality products and services.