I have read that amber lense glasses work best in brighter conditions and you can see more detail and a grey or grey/green tint is better for heavy overcast and will show more motion or I guess you could call it dark movement in the water. Personally I use light amber lenses most of the time and if I feel the need to switch to a grey lense I use a very light one. Photochromatic is actually a property of the lense and not the material the lenses are made of. A photochromatic lense will actually change the color of the light entering with minimal loss of it's intensity. A polorized photochromatic glass lense would in my opinion be the best and probably the most expensive as well as the heaviest. I have a problem with breaking or loosing my glasses so I buy reasonably priced light weight poly lenses because they have decent ocular characteristics and are more scratch resistant than plastic. Hope this helps.