“ACE”, short for Amethyst Contrast Enhancer, utilizes rare earth oxides in didymium glass composition to achieve unique color enhancing characteristics. This concept selectively positions transmission in the blue, green and red spectral regions, whereby one can improve color discrimination between different colored objects. ACE Glass is very efficient in filtering sodium flare in addition to providing ultraviolet protection to 390NM. It makes it very comfortable to view under high ambient light when working with glowing hot glass over a long period. Filters the sodium flare from 575 to 600NM. Comfortable, lightweight frames fitted with ACE Contrast Enhancement Glass. It is sometimes referred to as AUR 92 Glass. Has excellent color enhancing characteristics. Recommended for the serious professional hot glass craftsman who works with borosilicate (Pyrex Brand) as well as soda-lime (Soft) glass. Allows comfortable flame viewing over a long duration.