"I looked into this extensively and this lens is the best for low / flat light conditions. Also perfect for when skiing gladed runs. Optically very clear and the filtering of blue light increases brightness / contrast / definition. Easy to replace with the instructions supplied. It's better than the regular Persimmon Lens, as it has an IRIDIUM coating that reduces glare + the lens still features 100% UV protection - still important on an overcast day. Finally it has a Protection Index of 1, so when the sun starts to come out / partially out, you can still comfortably wear this lens without having to change."