Salmon Can Turn on Night Vision. Why Can’t We?

Most of us can only see certain wavelengths of light our entire lives. So why can salmon switch on night vision? We'll learn how they can reshape their eyes to see into the infrared.

Hosted by: Stefan Chin (he/him)
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[JackClayton]

My wife’s family (to me) are night blind. At light levels I think are more like a dim daylight level, they can’t see a thing. Comparing with my sisters, it seems I can see even more than them. Interesting observation.

[DoctorEyeHealth]

Fascinating! Thanks for sharing! I wonder how much vitamin A the med students were ingesting in that one study. Getting too much vitamin A can be toxic.

[susanburke]

I am just wondering where I can find more of Eric s. Work, I have been searching everywhere but I can not seem to find more. I do so enjoy Eric s talent in his expressions, filled with intrigue it has left me desperately in need to hear more. Please. There are many of us whom would be of great appreciation if we could find more of your great talent.

[tanamarn]

They can see further in NEAR infrared. Far infrared is heat, which can't be focused with a lens, but requires a sensor.

[FragmentJack]

“Even though humans will never be capable of this trick.”

You underestimate my power.

[sueshoemaker]

Since the salmon use their night vision in rivers is the switch triggered by the environmental change in salinity? Salty ocean water suppresses the formation of vitamin A2, fresh water turns it on? Not many fish can survive in both types of water but it would be interesting to know if other species that can do this also have night vision...

[dekutree]

I've always wondered why infrared vision isn't standard for animals. Wouldn't it be immensely helpful (and beautiful) if all living things were visually glowing? Why would evolution not select for such capability?

[favourus]

I checked the absorbance shift in the recent paper published in a journal. It is towards infrared but not infrared per se.

[AILIT]

With salmon being such a large part of my diet I'm just happy they have night vision and not net vision.

[darylbrown]

Question in the thumbnail ' Because we're not salmon!😂

[Thrashdragon]

On the internet, no one knows you’re a salmon

[casbot]

Salmon when they hear about how human name colours: _So you named a colour after me?_
_Is it silvery like my skin - hang on why is it light pinkish?_

*Why is it **_that_** colour....?*

[MadDragon]

My quadcopter has night vision. I love it!

[johnconnor]

Thank you, this WILL help my fish educating along nicely. I'm not a fisherman but a fish educator.
😎

[trapjohnson]

Not surprising that the increase of the vitamin alone does not come with the necessary enzymes that are compatible with our photo receptors to expand the range ;)

[vcostor]

Never say never. Only a Sith deals in Absolutes!

[kylehazachode]

We have a sort of night vision. Our cones are basically turned off it it's too dark letting our rods take over. Most of us will close one eye in the dark because stereoscopic vision doesn't work too well at night. The rods in our eyes are super sensitive to low light. Closing one eye in the dark lets one eye paint a better visual picture in our minds then two eyes struggling to make a stereoscopic image.

[jonatanromanowski]

Go Go Sci Show!
<Engagement boosting comment>

[KitTheMisfitToys]

I do think that under certain circumstances humans can evolve echo location that helps with sight. I was abused pretty badly as a child and had to learn as a child how to move around the house without making a sound, so i wouldnt be beaten if i needed to use the restroom at night or something. Now as an adult i can feel people walking in the house and when people are outside my house. Not exactly on topic but i am able to move through the house without lights and know when something is in my way because of vibrations i feel and kind of hear.

[cybrfriends]

"...and even though humans will never be capable of this trick..."
Florida man with genetic design starter kit, aka DIY CRISPR: "...are you challenging me?"