Eye specialists are of the opinion that extensive exposure of the human eyes to UV rays from the Sun can have significant impact which may damage cataracts, macular degeneration, pingueculae and pterygia and photokeratitis, etc., the part of eye. Several cases of temporary vision loss show the extent of the harm of UV rays; therefore, it is the best to wear spectacles which have been treated for UV rays wherein a layer is put on the glass to protect the deadly rays pass to the eyes.
Prescription sunglasses which contains or goes through UV rays treatment protects against harmful UV sun rays which otherwise can damage cataracts and macular. The design is important as a wrong one can have more damaging impact on the eyes. Similarly, scratch resistant coating on the prescription glasses helps sunglasses last longer in comparison to non-coated. The coating is done to the front and back of lenses during the process of making.
Though it is a fact that no lens can be considered scratch-proof, some can be made resistant which does not receive scratch when fall down or confront rough surfaces. Some companies offer scratch warranty wherein they replace the scratched piece with the new one. A scratched prescription sunglass should be avoided as this can affect vision. Before buying prescription sunglasses buyers should assure themselves about such a warranty and condition of returning.