Buying Specs On-line
If you want to purchase prescription eyeglasses online then you have to appreciate a few sensible steps before you get going. You can save a HUGE amount of money if you recognise how to buy your spectacles wisely and it they will be perfectly risk-free for you to utilize so long as you become cognisant of a few simple rules
Ensure that you have the exact fit
If your current specs fit fine, then just measure them up properly and you will need to have perfect fitting new specs online.
You need to know 4 measurements:
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Of these the most important measurement is the total width (A). Providing you have go the accurate total width, it doesn’t really matter if you have not got the height or width of your lens to get your online spectacles to be a good fit.
Ensure that you have the accurate lens prescription
There are a few parameters of your prescription that you will need to make a note of:
- Sphere – The amount of long or short sightedness. It is a measure of your lens optical power and is measured in diopters. It invariably will have a positive (+) or a subtraction (-) sign in front or above it.
- Axis – you will only get this if there is actually a value for the cylinder. It really is to do with the point that indicates the dirction in which the power of your cylindrical lens. It relates to a factor between 1 and 180.
- Cylinder – This refers to the degree of astigmatism that you possess. Once More, there is invariably a plus (+) or minus (-) sign present. You could find that your prescription does not have a cylinder value, if you don’t have an astigmatism.
- Pupillary Distance (PD) – This measurement is used to accurately center the lenses in the frame that you have selected. Technically, PD is the measurement of the distance between the centre of your pupils.
