Everything you need to know before you buy bifocal glasses online
Bifocal glasses are such glasses which help to fix multiple problems of the eyes including myopia and hyper myopia. The lenses used in such glasses are carefully crafted so that their two different parts have different focal lengths. With the help of their unusual construction, individuals can see both distant and closer objects quite clearly. Though these are quite helpful, bifocal glasses are much more expensive than conventional glasses.
The manufacturing process of such glasses is quite complicated. Earlier, two different lenses of different focal lengths were used in such glasses. However, with rapid advancements in technology, it has been made possible to craft a single lens in which another lens of different focal length is incorporated. This complex process of manufacturing these lenses has resulted in high price of these glasses.
In order to ensure that the two lenses match your requirement precisely, you need to provide your prescription to the online retailer from whom you are going to buy bifocal glasses online. If you happen to visit a good online store, you will find that it will have an intelligent application in place where you can specify focal length needed for correcting both near and far vision. Besides that, such an application will collect every bit of required information from you.
When you buy bifocal glasses online, you will be required to specify strength of your prescription and degree of astigmatism in diopters. Both of these need to be specified along with a sign. This sign is used to indicate farsightedness or shortsightedness. A positive (+) sign indicates that the lens is for farsightedness and a negative sign (-) will mean it is for shortsightedness. You will have to specify these features for both the lenses that you are going to use.
When any one suffers from astigmatism, he/she isn’t able to focus the light rays properly and as a result, what he/she sees is a blurred image of everything. It is a complex disorder and has a number of different types. The optician will check your eyes and determine the type of astigmatism with which you are suffering. At the time when you are going to buy glasses online, you may need to specify the axial length in order to specify the orientation of astigmatism.
In order to ensure accuracy in your eyeglasses, you need to provide the pupillary distance as well. This is the difference between pupils of the eyes. This is measured in millimeters and will be specified on your prescription quite clearly by the optician from whom you will get your eyes checked. It is very important that when you have to buy glasses online, you should take maximum information from the optician as a direct contact is not possible between you and retailer.
Whenever you are going to buy prescription glasses online, you need to provide complete information that you would have received from the optician so that the online retailer can provide you with such glasses which suit your requirements.