Lens types:   The cost of single vision lenses relies heavily on your prescription. The higher the value, the thicker your lenses are going to be. However, it is possible to upgrade to a higher lens index which is denser and stronger, thus making it thinner and more comfortable to wear. The higher the index, the thinner the lens.
Bi-focal lenses have two distinct vision fields. The upper portion usually has a prescription to see things off in the distance. The lower portion has a magnification so that one is able to read a book or newspaper. There is clearly a visible line separating these two visual fields.
Progressive lenses are also bifocals but the upper and lower portion of the vision fields are blended together, creating a seamless lens. They are also sometimes described as a no-line bifocal.  Not everyone is able to get used to progressive lenses, however. Wearing progressives or bifocals is only a matter of personal preference. Also, keep in mind that not all higher index lenses can accommodate bifocal or progressive prescriptions. The more questions you ask your optician, the better!
Coatings: Anti-reflective coating is recommended for those who wear glasses while driving or who spend long hours working on the computer. If you use your glasses just for reading, this coating isn’t really necessary.
Polarized lenses have become a popular trend lately but not everyone is happy with them. Their purpose is to reduce glare and haze while outdoors. When a surface reflects light, it will spread in all directions. Having polarized lenses reduces this glare and puts less strain on the eyes. However, there have been many complaints that people aren’t able to view LCD screens or mobile devices very well. Try them on and see for yourself if they’re comfortable or not, go outdoors and have a look at the world.
UVA/UVB protection is recommended, but if you wear your glasses for long periods outdoors or for day driving, it’s a must!
Tinting is only a matter of preference. Some like blue and purple tinting better than yellow, brown or green, and others feel the complete opposite. Try on the different colors available and have a look outside to see which you prefer the most. Please note that many people prefer yellow or brown tinting when spending long hours outdoors.
Scratch resistant coating is useful if you’re a little bit rough with your eyeglasses. For those who take their glasses on and off throughout the day (especially if they’re your reading glasses), chances of them getting scratched are much higher.
Reading up on what’s offered and asking yourself a few questions about what you’re going to need your prescription glasses for will save you money in the long run. Once you know what you need order glasses online and save even more!