Perscription glasses here, they work great, tint within a minute and would get them again. Have them on my safety glasses at work also.
Just remember transition glasses will not tint if your behind a UV protected window like driving your car or if your helmet has a UV protected shield. Only down fall is if it is a cloudy day as the UV rays are still there but the sunlight is not so the glasses will still tint making your view much darker on a cloudy day.