Lasers can cause damage in biological tissues, both to the eye and to the skin, due to several mechanisms. Thermal damage, or burn, occurs when tissues are heated to the point where denaturation of proteins occurs. Another mechanism is photochemical damage, where light triggers chemical reactions in tissue.
March 9: Teams are allowed to begin negotiating with other teamsâ players who are set to become unrestricted free agents at the end of the league year. This is the first time the NFL is providing a window to negotiate with other teamsâ free agents prior to the start of free agency.
Feb. 16: First day for clubs to designate franchise or transition players. Feb. 17-23: NFL Scouting Combine, Lucas Oil Stadium, Indianapolis. March 10: 2015 league year and free agency period begin at 4 p.m. ET. All clubs must be under the 2015 salary cap before 4 p.m. ET. March 22-25: Annual meeting, Phoenix. April 24: Deadline for restricted free agents to sign offer sheets.