If you have just encounter the term chakras and would like to know what they're, you have to exactly how that is known they work. I asked myself a similar question when I first heard of them. I could not recall any word like chakras inside my biology lessons. Now you understand what they may be, but the big question still remains about how to make use of the 7 chakras. A safer alternative is Bio-Identical Hormone Replacement Therapy (BHRT) which is derived from plants but treated to become identical to the body?s natural hormones. Since each individual is unique, BHRT doses can be customized to correspond exactly. Sunglasses allow better vision in bright daylight, and may protect one's eyes against damage from high levels of ultraviolet light. Typical sunglasses are darkened for protection against bright light or glare; some specialized glasses are clear in dark or indoor conditions, but turn into sunglasses when in bright light. Most sunglasses do not have corrective power in the lenses; however, special prescription sunglasses can be ordered. Specialized glasses may be used for viewing specific visual information (such as stereoscopy) or 3D glasses for viewing three-dimensional movies. Sometimes glasses with no corrective power in the lenses are worn simply for aesthetic or fashion purposes. Even with glasses used for vision correction, a wide range of designs are available for fashion purposes, using plastic, wire, and other materials.