Please, please, please make this switchable, luthier!
I am a pilot, fly single engine aircraft into the sun, and have no issue with PSE (
http://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I think it is great you are considerate to those who do have an issue, but the real pilots of WW2 did not have this filter (just sunglasses), and I would rather have no filtering.
Regards!
S!