Thread: Can darkness cause permanent blindness?

This question stems from a rather popular facebook/website 'factoid' saying permanent blindness can follow if a person has been in complete darkness for more than 3 days.

There are too many websites which state this, but just searching ''3 days of darkness cause blindness'' will get hits.

I'm skeptical. Most people do not have green eyes so we can rule out that the cells in the eyes rely on photosynthesis to survive.
Instead blood seems more reasonable as a method of keeping these cells alive.

Is there any evidence which either proves or disproves this legend? Not only have I seen it all over web factoid sites, but also in cavern safety leaflets.

I've seen this on cavern leaflets as well as on the web. I do not think that the eyes rely on photo synthesis to survive but I could be wrong.

http://realitypod.com/2012/07/3-or-more-days-spent-in-total-darkness-can-lead-to-permanent-blindness/

Originally Posted by FrankBaker

There are too many websites which state this, but just searching ''3 days of darkness cause blindness'' will get hits.

Yeah, and if you bother actually looking at those links you'll read things like this: However, there is no practical research supporting this.

Why did you create 2 threads?

Originally Posted by FrankBaker

Can darkness cause permanent blindness?

Doubtful.

Visual hallucinations during prolonged bli... [J Neuroophthalmol. 2004] - PubMed - NCBI


Edits: Here is an excerpt from the study on the procedures and with a link to the material.

Procedure: Subjects in the experimental groups were blindfolded for a period of 96 hours from 9 am on the first day until 4 pm on the fifth day. A specially designed blindfold was worn that prevented all light perception. It was held in place by a Velcro strap and further secured by Ace bandages. The blindfold permitted full motion of the eyes as well as opening and closing of eyelids. Potential tampering with the blindfold by the subjects was controlled with the use of a piece of photographic paper attached to the inside of the blindfold...

Results: ... Vision returned to normal approximately 30 to 60 minutes after sight restoration...

Link

Originally Posted by Dywyddyr

Originally Posted by FrankBaker

There are too many websites which state this, but just searching ''3 days of darkness cause blindness'' will get hits.

Yeah, and if you bother actually looking at those links you'll read things like this: However, there is no practical research supporting this.

Why did you create 2 threads?

I did? I must've hit 'submit' twice after my browser didn't re-direct

If any mods see this, delete the duplicate, I didn't know I'd posted it till you mentioned

Originally Posted by scoobydoo1

Originally Posted by FrankBaker

Can darkness cause permanent blindness?

Doubtful.

Visual hallucinations during prolonged bli... [J Neuroophthalmol. 2004] - PubMed - NCBI


Edits: Here is an excerpt from the study on the procedures and with a link to the material.

Procedure: Subjects in the experimental groups were blindfolded for a period of 96 hours from 9 am on the first day until 4 pm on the fifth day. A specially designed blindfold was worn that prevented all light perception. It was held in place by a Velcro strap and further secured by Ace bandages. The blindfold permitted full motion of the eyes as well as opening and closing of eyelids. Potential tampering with the blindfold by the subjects was controlled with the use of a piece of photographic paper attached to the inside of the blindfold...

Results: ... Vision returned to normal approximately 30 to 60 minutes after sight restoration...

Link

Thanks for that. I follow quite a lot of ''factoid'' pages on Facebook so I've come across the statement a few times and I just got around to questioning it.

Finding the occassional oddities on the social media and being skeptical enough to find out if its true is a good thing. A better way to advance our own education outside of a school environment is to try a do a little "research" for relevant studies on our own, and if we're unsuccessful in our google-fu, there may be others here who may be able to point us in the right direction.

sometimes you have surgeries and they cover you eyes for several days.......and you are light sensitive when they let you take the stuff off...but blind?....pfffffffffft

You don't really need science to know this is Bravo Sierra...practical knowledge and common sense should tell you otherwise. Countless prisoners have been kept in solitary confinement in total darkness for way more than 3 days...and don't come out permanently blind...and there are many other examples.

Giant Duuuuuuh!

It's just another "Three Musketeers" thread from the sockpuppet.

I've heard that if you spontaneously combust (ideally at negative temperatures) for 3 days you go blind.
Is that correct?

Don't start two separate threads about the same subject.

Originally Posted by scoobydoo1

Finding the occassional oddities on the social media and being skeptical enough to find out if its true is a good thing. A better way to advance our own education outside of a school environment is to try a do a little "research" for relevant studies on our own, and if we're unsuccessful in our google-fu, there may be others here who may be able to point us in the right direction.

What I don't understand is why muscle cells atrophy from under-use while eye cells seemingly (from the evidence provided) do not

Photoreceptors in eyes aren't made of muscle tissue.

Originally Posted by Daecon

Photoreceptors in eyes aren't made of muscle tissue.

True. Photoreceptors are specialized cells which contain proteins that are bound to light-absorbing molecules that mediate visual phototransduction.

Originally Posted by FrankBaker

permanent blindness can follow if a person has been in complete darkness for more than 3 days.

The closest to the truth regarding such a claim is that, if a newborn is deprived of all light, its brain's vision centers will not develop properly. I don't know if the result is permanent. It won't cause total blindness because babies are born with the fundamental circuitry for vision.

source

Originally Posted by PhDemon

It's just another "Three Musketeers" thread from the sockpuppet.

Don't insult the Three Musketeers!! *L*

I didn't, I insulted the OP by reference to that work (and it's author)

Originally Posted by PhDemon

I didn't, I insulted the OP by reference to that work (and it's author)

You ARE a BRAT!! SIR!

What? I just pointed out the OP (like the Three Musketeers) is the work of A. Dumas(s)

Originally Posted by PhDemon

What? I just pointed out the OP (like the Three Musketeers) is the work of A. Dumas(s)

Two of my friends and I are THE THREE MUSKETEERS....and we are formidable! *L*

An extreme vitamin D deficiency might harm the eyes, but that would take a very long time in the dark.