For the past six years Seadive/Oceanways has developed and field tested, anti-reflective (ARC) mask coatings of tempered glass. Seadive/Oceanways ARC coatings now allow almost 100% transmission of light. Standard tempered glass has a minimum of 4%-plus rate of reflection which can seriously distort underwater vision. Only Seadive/Oceanways offers Rayblock fog-free lens masks. Only Seadive/Oceanways has licensed application and laboratory fabrication. Only Seadive/Oceanways has six-plus years of dealer/customer satisfaction. XS Scuba's Seadive Rayblock Eagleye SLX HD Mask provides the Best overall for any and all diving/snorkeling conditions". The lens reduces harmful UV/glare, surface grit in eyes and provide overall greater clarity. When you come up for a dive the lenses provide quick vision-return from surface making this the instructor's choice in mask design.