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

Tags: short corridor, Varifocal Glasses, varifocal lens

This entry was posted on Wednesday, May 27th, 2009 at 1:56 pm and is filed under Glasses, Varifocals Online. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.