Dr Joseph Allen

So the challenge is that when you have salt, it'll draw fluid into the tissues.

And so if people cry the night before, the salt remaining in the tears basically get into the tear ducts and sit on the surface of the eye and the eyelids, and then that can draw fluid into those tissues.

Does hydration play a role in that?

That's also something that's been looked at in research.

It's not really conclusive.

I think hydration is still something we need to – I do encourage people to at least be aware of their hydration.

for dry eye, there is some research that indicates that people who drink more water tend to have less severe symptoms of dry eye.

That, again, I recently did a live stream where I did research first and tried to look into this.

And they have looked at quality of sleep, time of sleep, and both the subjective and objective appearance of dark circles under the eyes.

And they find that it is if you have not been getting good sleep, objectively your under-eye dark circles do not change.

But your subjective appearance of your own image will go down.

So they find that for both sleep and stress.

Because they can measure the type of light being reflected off the surface of your skin, so they can see how much pigment and what type of light is being reflected.

And so they've been able to find, oh, that it's purely just your subjective opinion of your own self-image

seems worse when you're tired.

So at least in the few studies that I've been able to read that were published in the last five years, don't seem to find that conclusive.

There are other physiological changes that happen when people don't sleep or are under stress, right?

Cortisol releases, inflammation in the body will change, hormones can change.

So they may all play a role there.

But right now it seems to have a less effect on the true pigmentation of the eyelids.