Hi, I am a CL on another forum, but this is a topic I've wanted to speak to others about for a long time. Before I was disabled with MS I was a pediatrician for 23 years. Before that I was an outdoor lifeguard in Southern California. I discovered a way to see sunburn before it completely develops with pain and redness.
I hope this isn't inappropriate for this new forum.
I always chose to wear brown tinted, instead of gray tinted, sunglasses when I was a lifeguard. I discovered that with the warm brownish tinted glasses I could see that kids (or adults) were becoming sunburned long before their skin became painful or red with the naked eye. I would often warn parents that their kids were burning. Most ignored me and said their kids looked fine.
But, occasionally, the parents or kids would doubtfully heed my warning and get out of the sun. Many times these poeple spoke to me later, thanking me for saving them from a bad sunburn. They found that as the sun's effect developed they saw and felt the mild burn later that evening and were very glad they had stopped it from being worse.
The warm color of the sunglasses accentuates the mild redness that comes with burning and makes it visible befire the burn is very bad and before the redness is really visible. Since those life-guarding days I have had several instances of being able to warn friends of an impending burn.
This wasn't any kind of a controlled study, but it worked many times. I just wanted to offer this tip to people and parents as a way to know much earlier that someone was getting too much sun.
Quixotic1