Buying Varifocal Glasses — A Guide
In case you have trouble with both short-sightedness and long-sightedness then varifocal glasses could be the thing for you.
Varifocals include two sight corrections in an individual lens, one to correct your short-sighted vision and one for the long-sightedness. Before varifocals, getting two sight corrections within one lens required bifocal glasses. Bifocal glasses are a short-sight correction lens that has a separate long-sight correction lens contained in a small area in the lower half of the lens. The disadvantages of this though are that to use your long-sight correction you have to take care to look using a small lens area at the bottom of the lens. These glasses also often look unsightly.
For the wearer, the prescription of the varifocal lens adjusts progressively from the top to the bottom of the lens. As a result near sight tasks like reading a paper the wearer simply uses the lower half of the lens. For long-distance tasks like driving, you simply use the top half of the lens. Varifocal lenses are now fitted in many of glasses frames that you can buy, there are though a few issues to bear in mind.
The biggest problem is the size of the frame. To house two lenses within a single frame, there is a need for the lens to have sufficient vertical distance for the prescription to change. There are ways around this, though. Many varifocal prescription glasses require a height of at least 25mm so as to function properly. Now, though, you can often buy short corridor varifocal lenses that can be housed in frames less than 25mm high, and often as small as 13mm.
When you want to buy varifocals online, you may select from a range of lens thicknesses. For effective prescriptions, the lenses in standard varifocal glasses tend to be quite thick which some wearers find unattractive. For infrequent wear, this doesn’t particularly matter, but if the glasses are your main pair, you may consider a thinner alternatives.
Note that when you want to buy varifocals online, as with other types of glasses, coatings are available for varifocal lenses such as scratch protection, anti-glare coatings, and tinting. As varifocal lenses are usually a factory order, some coatings are not available on all lenses. This may affect your choice as to which lens option to select, depending on your requirements.
To order varifocal glasses over the internet, a prescription is needed from opticians. Along with the standard order information, there are a few additional particulars that will be required.
Specifically, your supplier will need the pupillary distance. This measurement is the distance in millimeters from one pupil to the other. This should ideally be measured by an optician. However, if necessary, it can be taken at home by using a ruler and the assistance of a friend.
Varifocal glasses offer a huge step forward in improving the vision and looks of anybody with both long and short-sightedness. Now you can buy them online, cheaper and speedier than ever before, so why to wait. Make your world a little clearer today.