It can be challenging to choose the perfect prescription glasses while shopping at an online store. It is hard to determine the styles that suit you because you cannot wear it and see yourself at the mirror. Many online stores have a try on facilities. The try on facility let you know how you look when wearing the frames.
You have to decide the materials of the frame. Most of the eyeglass frames are made from plastic or metal. Metal frame can get rusty. If you want a durable frame, you can purchase the plastic frame. Next, you should decide on the type of lens you want to use in your prescription glasses. The lens can be made from polycarbonate, high index, plastic or glass. Glass lens is fragile because it can shatter into pieces when you accidentally drop it on the floor. Plastic lens will not break if you drop it. High index lenses are from a type of material that can reflect the light. The refractive index is used to measure how much light it can bend. Effective high index lenses have a high refractive index.
After that, you must select the types of coatings for the lenses. Ultraviolet coating call protects your eyes from the ultraviolet ray. The ultraviolet ray can harm your eyes so it is best to purchase prescription glasses with ultraviolet coating. The anti reflective coating prevents the prescription glasses from producing a reflection.
The types of vision problem will affect the shapes of the lenses. Lenses that curve inward are for people with farsightedness while lenses that curve outward are for people that have nearsignedness. There are several types of lenses you can choose from including trivex lenses, polycarbonate lenses, aspheric lenses and polarized lenses. Trivex lenses are plastic lenses that offer the same characteristic as the polycarbonate lenses. The advantages of a trivex lens are lightweight and resistant against heavy impact. The polycarbonate lenses are preferred by athletes because they have a strong resistance against the heavy impact. Aspheric lenses have different degrees of curvature. It is much thinner and flatter compare to other lens. The polarized lenses are tinted with a dark or light color. The purpose of tinting the lenses is to block the sunlight from shining into the eyes. Polarized lenses are used in prescription sunglasses.
You need to obtain the distance between the pupils. The measurement of the distance between the pupils is called papillary distance. The papillary distance is usually not included in the prescription so you have to measure it yourself.