High-index and aspheric lenses

"If you need high-powered lenses you can improve the weight or appearance of your glasses with special lens materials and designs. High-index lens materials and aspheric designs mean that lenses can now be made thinner, lighter and better looking than traditional lens types. High-index materials and aspheric lens design make lenses for short sight and long sight thinner and allows more optimal vision through the lens area away from the centre of the lens"

Prescription Sunglasses

"Whatever your prescription, it is important to protect the eyes against excessive ultraviolet (UV) radiation. Protection is needed to avoid reflected light from sand and snow or if you spend long periods outdoors, particularly in the summer. Prescription sunglasses can be made with single-vision, bifocal or varifocal designs to offer the same standard of protection as non-prescription sunglasses. Only costs an extra £10 (online price, may cost a lot more on the high street) for having the sunglass tint put on the glasses, worth while in the long term"

Scratch-resistant / hard coating

"Plastic lenses are lighter than traditional glass lenses but they scratch more easily. Scratched lenses can be irritating for the wearer and look unsightly. Scratch-resistant coatings are available to protect against damage and prolong lens life."

Anti-Reflection Coating

"Spectacle lenses can be provided with anti-reflection coatings which virtually eliminate distracting reflections off the lens surfaces. Reducing reflected light is particularly helpful for computer users and for night driving. Anti-reflection coatings also improve the cosmetic appearance of your glasses and can make thick lenses look thinner."

Varifocal Lenses

"Varifocal lenses, also known as progressive lenses, are used for correcting presbyopia but unlike bifocal lenses, varifocals have no visible dividing lines between the different corrections. Instead they have a graduated section in which the power of the lens progresses smoothly from one prescription to the other, allowing the wearer to see clearly at all distances. These lenses also have the benefit of looking better - they don't draw attention to the ageing process. A range of varifocal designs is available depending on your lifestyle and occupation. Modern lens technology means that there are many different designs and materials to choose from. Your optometrists or dispensing optician will be able to advise you on the best lenses to suit your individual requirements."

Bifocal Lenses

"Bifocal lenses contain two optical corrections with a distinct dividing line between the two parts. The most common use of bifocals is for people who have become presbyopic and need a different prescription for close work. The upper part of the lens corrects distance vision and the lower half is for near vision. Trifocals are also available that have three sections and incorporate a correction for intermediate vision. Bifocals and trifocals come in a range of designs. Bifocals or varifocals are more commonly prescribed than trifocals"

Single Vision Lenses

"The simplest form of spectacle or contact lens is the single-vision lens, made to a single prescription to correct a particular eyesight problem. Concave lenses are used to correct short sight and convex lenses to correct long sight. Concave lenses are generally thinner in the centre than they are at the edge and convex lenses are usually thinner at the edge than at the centre. The curvature of the lens, its thickness and weight will depend on the amount of long or short sight it is designed to correct. The lens material will also influence the thickness and weight of your lenses, as will the size and shape of the spectacle frames you choose. Traditionally, spectacle lenses were made of glass but most lenses are now lightweight plastic (1.5 cr39) and there is a wide range of materials available to suit your prescription and lifestyle."

PD (pupillary distance)

Glasses Complete "* PD (pupillary distance);

PD is the distance from the centre of the pupil (black circular area) in one eye to the centre of the pupil in the other eye.
Your optician may or may not give you the PD (the optician is not required to do so as part of your eye test). Your optician can provide this measurement as your PD is always measured during an eye test. We therefore recommend that you ask for it when you have your eyes tested.
Alternatively, you may choose to use an average PD, which is provided for you by our dispensing optician on the order form.

In many high street opticians, sales staff with no optical qualifications take PD measurements. Therefore, If you would like to measure your own PD, you can do so by taking the following steps:

1. You need an assistant (a friend!) to help you.
2. You need to Focus on a fixed point in the distance, for example; window at the end of the room.
3. Whilst you are focusing on the distance, with a ruler your friend measures the distance between the centres of one pupil to the centre of the other in millimetres. The average PD is normally between 54 and 70mm.
4. When difficulty is experienced in determining the centre of the pupil, the edge of the pupil or iris may be used as a measuring point if both pupils are the same size. Measurement is read from the left side of one pupil to the left side of the othe other pupil.

OR you can do it yourself by looking in the mirror.

Your Prescription Explained

Glasses Complete : Your Prescription Explained: Prescription copies that are given to you by the optician follow a certain format:

Mr Smiths Example Prescription:

• Right and Left

On all prescription copies there is a section for the Right eye and a section for the Left eye (marked just R & L sometimes).

• Distance and Near

Distance and Near sections (occasionally intermediate section).

The following sections are completed by the optician:

• Sph, Cyl, Axis, Prism, Base, Near, Intermediate

Sph and cyl sections have a number which represents the power in 0.25 steps, EG, 0.25, 0.50, 0.75, 1.00, 1.25 and so on, with a ‘+' or '-' sign. (If zero strength is required then the relevant section is left blank or contains PLN or µ).

Axis section has a number if required, ranging from 1 to 180. No + or – notations.

Prism section has a number, and the base section has up/down/out/in (which is rarely required).

Near part is usually referred to as the "ADD" or "Addition". This value is again seen in 0.25 steps, E.G: 0.25, 0.59,0.75 and so on. The reading add is always accompanied with a ‘+’ sign. The reading addition / Add is combined to your Distance prescription, by the lab technician, to ascertain your Reading Prescription or for Bifocals.
Some opticians will write out your complete near prescription (with sph & cyl/axis) underneath your complete distance prescription. This gives the same information as the above.

Intermediate Part is not always specified, however, if it is required it comes in the form of an "ADD" or "Addition". This is the Addition combined to your Distance prescription to ascertain your Intermediate Prescription (not always prescribed by the optician).

Some opticians will write out your complete intermediate prescription (with sph & cyl/axis) underneath your complete distance prescription. This gives the same information as the above.