Ultraviolet, or UV, light is used to "cure" acrylic nails, causing them to harden and adhere to the existing natural nail. The UV light is used to ensure the acrylic nails are solid, secure and last for a long time.
The acrylic nail system can lengthen or decorate nails. Acrylic nails are popular because they can artificially lengthen natural nails or solidify nails at a given length from several weeks to as long as a month and a half. Because of the acrylic liquid and powder used, UV light is required to stimulate the chemical connection between the acrylic formula and the natural nail.