With conventional sunglasses, two spectacle frame supports are worn at the ears. The spectacle frame is supported by the wearer's nose ridge. The wearer's spectacles may slide down due, e.g. to sweating after they are worn for long time. In this regard, the wearer of the spectacles may feel uncomfortable due to this defect. Besides, when the sunglasses are not in use, they must be folded, often with trouble. If they are damaged, the sunglasses are not easily repaired back to the normal condition.
The front edge of sunglasses or goggles is flat and horizontal, which can not effectively shield eyes from the sunlight, Ordinary goggles are made up of plastic material and are fixed in form. They do not accommodate different types of wearers' faces. Thus, there are many defects in conventional sunglasses and goggles.