SPHERE - The sphere (SPH) number denotes the strength of the lens , in Diopters (?).
CYLINDER - Indicates the presence of Astigmatism. If Cylinder (CYL) is none, astigmatism is not present.
AXIS - If Astigmatism is present, represents the necessary correction, in degrees.
ADD - The (positive) Addition , in Diopters (Δ), required for close up (reading) prescriptions.
PRISM CORRECTIONS - If present, corrects vision displacement, just as double vision, or for people whose eyes are not perfectly aligned.
PRISM VALUE - Prism, in Diopters (Δ), necessary to correct eye alignment.
BASE DIRECTION - Direction (Up, Down, In, Out) in which to apply the corresponding Prism Value alignment.
PUPILLARY DISTANCE (PD) - The horizontal distance (mm) between the center of your pupils. It ensures the center of each lens is correctly aligned with the pupil of each eye.
PRESCRIPTION DATE - Must be within the last two years to be valid.
ADDITIONAL INFORMATION - Any special requests or other relevant information.
POWER - The magnification required for your reading glasses, in Diopters (Δ)
Standard (1.5) - Our Standard 1.50 Index lenses are made of CR-39 Plastic and provide excellent optical quality and are ideal durable lens for everyday purposes. Recommended for low prescriptions with SPH ranging from -2.00 to +2.00. If your prescription is above +/-2.00, we recommend that you upgrade your lens.
Thin and Lite (1.56) - Our Thin and Light 1.56 Index lenses are up to 15% thinner than Standard 1.50 index lenses and are recommended for those with moderate prescriptions who would like a lighter and thinner lens. Recommended for prescriptions with Sphere (SPH) values in the range -4.00 to +4.00
Polycarbonate (1.59) - Our Polycarbonate 1.59 Index lenses are highly impact resistant and are ideal for sporting activities, as well as for children's glasses, and they also block 100% of harmful UV rays. Recommended for prescriptions with Sphere (SPH) values in the range -4.00 to +2.00
Super Thin (1.61) - Our Super Thin 1.61 Index lenses are up to 20% lighter and thinner than Standard 1.50 index lenses and are recommended for those with moderate to high prescriptions with Sphere (SPH) values in the range -6.00 to +4.00.
Ultra Thin (1.67) - Our Ultra Thin 1.67 Index Aspheric lenses are up to 30% thinner than Standard 1.50 index lenses and are recommended for Prescriptions with Sphere (SPH) values above +/- 4.25.
As Thin as Possible (1.74) - Our As Thin as Possible 1.74 Index Aspheric lenses are the thinnest, lightest lenses on the optical market today and are up to 35% thinner than Standard 1.50 index lenses and are recommended for Prescriptions with Sphere (SPH) values above +/- 4.25.
Scratch-Resistant - Scratch Resistant hard coating protects your lenses against minor scratches.
Anti-Glare - Our premium anti-glare coating to your lens reduces reflection on the surface of the lenses is perfect for computer use and can help makes night time driving easier.
UV Coating - Give your eyes more protection! Overexposure to UV light may cause eye problems that are preventable by placing a UV coating over the lens. Invisible to the naked eye, our UV (ultraviolet) coating provides superior protection for the eyes without changing the appearance of the lens.
Water-Resistant - A special Water-Resistant (Hydrophobic) coating that also improves the scratch-resistance.