Guides

Useful terms

The optical jargon you will meet when buying glasses, decoded.

Your prescription choices

Distance — single vision: Single vision lenses for distance, nearsighted or shortsighted corrections (myopia).
Reading (prescription): Single vision lenses for close-up, farsighted or longsighted corrections (hyperopia).
Progressive: For distance, intermediate and near vision with a smooth transition and no bifocal line.
Bifocal with line: Multifocal, for distance and near vision, with two distinct fields of vision separated by a bifocal line.
Readers (OTC): Non-prescription over-the-counter lens, for magnification (reading) only.

O.D.: The right eye (oculus dexter).
O.S.: The left eye (oculus sinister).
SPHERE: The sphere (SPH) number denotes the strength of the lens, in dioptres (D).
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 dioptres (D), required for close-up (reading) prescriptions.
PRISM CORRECTIONS: If present, corrects vision displacement, such as double vision, or for people whose eyes are not perfectly aligned.
PRISM VALUE: Prism, in dioptres (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 in millimetres between the centres of your pupils. It ensures the centre of each lens is correctly aligned with the pupil of each eye. See what is PD.
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 dioptres (D).

Standard (1.50): Made of CR-39 plastic, providing excellent optical quality, and an ideal durable lens for everyday purposes. Recommended for low prescriptions with SPH from −2.00 to +2.00. Above ±2.00 we recommend upgrading.
Thin and Lite (1.56): Up to 15% thinner than standard 1.50 index lenses, recommended for moderate prescriptions with SPH from −4.00 to +4.00.
Polycarbonate (1.59): Highly impact resistant, ideal for sporting activities and for children's glasses, and blocks 100% of harmful UV rays. Recommended for SPH from −4.00 to +2.00.
Super Thin (1.61): Up to 20% lighter and thinner than standard 1.50 index lenses, recommended for moderate to high prescriptions with SPH from −6.00 to +4.00.
Ultra Thin (1.67): Aspheric, up to 30% thinner than standard 1.50 index lenses, recommended for prescriptions with SPH above ±4.25.
As Thin as Possible (1.74): Aspheric, the thinnest and lightest lenses on the optical market today, up to 35% thinner than standard 1.50 index lenses. Recommended for prescriptions with SPH above ±4.25.

Scratch-resistant: A hard coating that protects your lenses against minor scratches.
Anti-glare: Our premium anti-glare coating reduces reflection on the surface of the lenses. Perfect for computer use, and it can make night-time driving easier.
UV coating: Overexposure to UV light may cause eye problems that a UV coating prevents. Invisible to the naked eye, it provides superior protection without changing the appearance of the lens.
Water-resistant: A hydrophobic coating that also improves scratch resistance.

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