BZ Optics were the first company in the world to develop bi focal photochromic sunglasses, featuring high impact UV activated photochromic lenses which transition from clear (Cat0) in low or no light to grey (Cat2) in full sun.

All PHO lenses are interchangeable

All our sunglass lenses block harmful light and offer 100% protection from both UVB & UVA rays.

- UV400 protection.

What's the difference in lens categories?

Category 0 - No tint, with light transmission at 80% to 100% - For pre dawn, overcast days and dusk or night.

Category 1 – Light tint, with light transmission at 43% to 80% - For cloudy days.

Category 2 – Medium tint, with light transmission at 18% to 43% - Good for all but the sunniest days.

Category 3 – Dark tint, with light transmission at 8% to 18% - For very sunny days.