When we pay more attention to the appearance of a pair of eyeglasses, we should concern about various kinds of frames with different classification. However, if you hope the eyeglasses you choose are more pragmatic and functional, you may need to devote more time and energy to make lenses selections.
For people who want to order prescription lenses online, it is necessary for them to input their online prescription list. First of all, they should know what kind of eyeglasses they would like to choose according to their vision status. For example, if they are difficult to see both the near and distance objects, they should choose bifocal eyeglasses or progressive eyeglasses. Then, there may refer to CYL, SPH, ADD in the prescription list that should be input so that online sellers can prescribe the RX eyeglasses according to the information. Many people think they have finished their tasks already at this time. However, they are reminded to write the PD number which is the distance between your pupils in millimeters. The PD is important for accurately fitting the RX lenses to achieve vision acuity. The single vision only has one PD and the two-focus eyeglasses involve in two PD including right PD and left PD. If you want to buy bifocal or progressive eyeglasses, your PD value is very important. You can get your PD from you eye doctor.
Like the frame, we also should lay stress on the lenses image. The lenses which are too thick will be much ugly and heavy to wear for wearers. Especially for people who have strong prescription, they should choose the high index lenses which can decrease the weight and thickness to some degree. You may cost a little bit more buy the high index lenses. However, it is really worth as you can enjoy long-term comfortable wear.
People who have serious requirement to their RX eyeglasses can pick out their lenses materials. There are several kinds of lenses materials like glass, resin and CR-39. Glasses lenses are the traditional type that are much cheap but quite heavy to wear. Resin is a little advanced, which make the lenses light weight compared with glass lenses. However, they should be worn in a good condition. CR-39 is a latest invention that owns many advantages like light weight, more resistance and they also can shock to hot and cold conditions. Of courses, it will be much expensive than other two types of lenses.
- What are the disadvantages of wearing progressive glasses?
- How big does a frame need to be for progressive lens?
- How to get used to progressive glasses quickly?
- What are the advantages of progressive glasses over lined bifocals ?
- Do I still need computer glasses if I have progressive glasses?
- What is the difference between trifocal and progressive glasses?
- I have difficulty reading newspaper and computer with my progressive glasses?
- What kind of progressive glasses provide a good intermediate reading zone?
- What size of lens should I choose for progressive glasses?
- Are all no line glasses progressive?