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Comment by Equiet | Hacker News Reader

There's a video which shows how you look like to a UV camera when you put sunscreen on. Also glasses with UV filters: https://www.youtube.com/watch?v=o9BqrSAHbTc

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The video was cool but I'd also be skeptical of how they imply that freckles (including UV spectrum freckles) are "damage" to the skin or undesirable. It's neat that people look different under UV, and it's a cool adaptation that our skin pigments seem to target UV differently that visible spectrum... that's all I would confidently take away from the video

But in many (most?) cases, they are damage. I have visible 'freckles' in my shoulders. I wasn't born with them. There's further damage in some areas that had heavy exposure to sunlight. Same on the more exposed areas in my arms. Zero "freckles" or spots of any kind outside these zones. There's plenty of literature on this.

Sure, they are an adaptation. One that's best avoided _while you can_

Every time you get a "sunburn" and your skin turns red? That's DNA damage. The body is good at repairing that, but not perfect. Best not to take damage in the first place. And if you do, to at least reduce the total radiation amount.

We shouldn't be singling out people based on their appearance of course. But there should be more awareness that skin damage is cumulative, and skin should be protected as much as possible.

I regret not having done so when I was younger. As much as I hate sunscreen.

>Sure, they are an adaptation. One that's best avoided _while you can_

Why do you want to avoid this damage?

Sun exposure and solar elastosis (sun damage to the skin) is associated with reduced mortality from melanoma:

https://academic.oup.com/jnci/article/97/3/195/2544082?login...

and a literature review which backs this up:

https://adc.bmj.com/content/91/2/131.short

And sun exposure reduces all-cause mortality:

https://onlinelibrary.wiley.com/doi/full/10.1111/joim.12251

This comment is full of assumptions about an extremely complex and poorly understood relationship between two things that are themselves very complex. The fact is, we evolved to live in the sun, just as most other land animals did. While it can damage us (just as anything in nature) it's unclear to what extent this damage might be offset by the benefits of sun exposure, or to what extent sun exposure might have a hardening effect against further damage, extending the benefits even further. Sunscreen didn't exist for most of human history, and yet there were no plagues of skin cancer. The fact is, we simply cannot say with any certainty that "the skin should be protected as much as possible".

I live in south Florida (tropical weather climate) and my shoulders are covered in freckles from sunburns growing up. Basically following the sunburn the skin would begin to peel, which started off as little circles (which I always assumed became the freckles).

I don’t know much about the process but always classified it myself as damage/scars. Though I could see calling non-sunburn induced freckles scars or damaged skin (or undesirable) as being inaccurate and just insensitive to people born with freckles.

My ultimate dream is a pair of magical glasses with a small knob on it, which when turned adjusts the wavelength you can see from deep radio all the way to high energy gamma. Just imagine seeing the entire spectrum.

You want Geordi's VISOR from Star Trek.

The episode where they hook up his visor so they can display what he sees on screen was always cool to me.

I know I do!

Yes!!

Not sure the other spectrums of light are intense enough on average for such glasses to work without them also emitting all spectrum of light (essentially a walking radar/lidar/X-ray/etc… machine).

For example we of course have these types of “glasses” for infrared which is fine for humans because we give off significant quantities of infrared radiation, but lesser known is we also emit light in the visible spectrum, it’s just not enough intensity for our rods/cones or inversely our rods/cones are not sensitive enough to observe the visible light we emit. Anyway your invention would be cool, even if it just ratcheted up the existing visible light spectrum enough we could see ourselves glowing in the dark…it would give people a new appreciation for Carl Sagan’s quote that we are made of stardust.

Thanks.... but now I need to buy a UV pass filter for my hyperspectral camera.

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