When deciding what style and size of glasses to order, there are several things to consider that will affect the size of the lens as well as the appearance of the finished spectacles.

If you are very short-sighted, the lens will become thicker as it progresses out from the centre of the lens or glasses frame towards the edge. Things to consider therefore are :

• Try and select a frame that fits in proportion with your face – but with a small(er) lens where possible. This will tend to make the lens and hence the glasses thinner and lighter.
• If possible, use a high index material for your lens selection. Standard lenses are 1.5 or so – if your prescription is quite acute, moving to (more expensive !) high index lenses can have a substantial impact on the thickness and so the weight of the lens and spectacles. The delta from standard lenses to 1.74 lenses can be as much as 45%.
• Get glasses lenses with an anti-reflective (AR) coating. Eliminating lens reflections will make your lenses look thinner, and provide better vision when driving at night.

If you are very farsighted:

• Choose a smaller frame. A frame with a smaller lens area will reduce the thickness of your lenses and the overall weight of your eyewear.
• Choose an “aspheric” lens. An aspheric lens design will make your lenses flatter and reduce unwanted magnification that can give you that “bug-eye” look with regular lenses with a high prescription for long sight. Aspheric lenses also provide better peripheral vision if you are farsighted.
• Avoid rimless frame designs. Lenses for longsight sometimes have to be made thicker to fit in this type of frame.

If in doubt, call us on 0151 632 6611

or visit our website for helpful information :  www.Spex4Less.com

Varifocal glasses are significantly more difficult to correctly fit and assess than standard spectacles - whether single vision or bifocal.

The predominant reason for this is that there is a transition within the lens to accommodate both the “distance” prescription as well as the “near” lens prescription. Because of this transition, it is also necessary to be able to accommodate a “neutral” prescription as the lens migrates from one prescription to another

This almost always necessitates a large type frame and lens - the standard requirement is for a depth or space of 21mm from the point at which the lens is centred on the iris to the bottom of the lens……….and hence the lens needs to have a total dimension of > 42mm.

There is an alternative known as a “short corridor” lens that reduces this dimension to as little as 13mm - hence enabling varifocal lenses to be fit into much “narrower” frames.

Varifocal glasses lens options

In either case, obviously good measurement is required both for the choice of lens and to ensure that the galsses sit effectively on the face and deliver results that are satisfactory for the user.

Information on how we do this can be found at

http://www.spex4less.com/varifocal_glasses.shtml