Personally, when i had a choice of lenses, I almost never wore very dark lenses, even on a very bright sunny day. Just occasionally, the target will be into the sun itself, so then it is a help. The nice dark lenses you would wear around the pool feel relaxing, but for picking out clays, I always go with the lightest ones I can, as long as I am not squinting. Dark is fine if every target is against a blue sky, but as soon as its against some trees or whatever, it can become tricky. Wearing a cap with a peak helps a lot with glare.