Genetically engineering protection against flashbangs?

Question

I'm referring specifically to the "flash" part of the flashbang (although advice on the bang part would also be appreciated).

One animal feature besides night vision I thought might be useful to splice into next generation's genetically-engineered super-soldiers is a nictitating membrane. Animals use them to keep their eyes moist and clear of dust and debris in harsh conditions without having to blink, a trait which might be useful in a desert combat environment or underwater/out at sea. Humans already have the small vestigial remains of such membrane, so I figured that with coming advances in genetic engineering, soldiers equipped with such membranes wouldn't seem too implausible a few decades from now.

But then I thought bigger. If we're already talking about giving soldiers built-in eye protection, what about protection from flashbangs and other sources of bright light, like bombs and tracer rounds? Could a nictitating membrane be further modified into a self-darkening membrane that folds over the eyes to protect them like welding goggles? Is there any natural source I could take such a self-darkening mechanism from, or would I have to augment my spliced-in membranes with some sort of artificial self-darkening filter?

Answer 1

A membrane resembling a nicitating membrane would not do what you want:

• The membrane is not designed to be seen through, so its optical properties are horrendous.
• If the membrane is in place, you would not be able to see unless the area was illuminated by a flashbang. Flashbangs go off far too quickly to move the membrane in place in response to the flashbang.
  • If you note: welding goggles are virtually impossible to see through when they are dark. If you have the auto-darkening kind, they protect against the continuous bright light of an arc. They are completely ineffective against impulses of light such as a flashbang.

It'd be more effective to explore how to recover after a flashbang goes off. We might be able to send our eyeballs a "reset" command to tell them to flush whatever chemical effects had occurred in response to the light and start processing the scene again.

Answer 2

Essentially what we are describing here is a bright flash of light, not sufficient to injure the skin but enough to stop the eyes from functioning.

According to wikipedia:

The flash produced momentarily activates all photoreceptor cells in the eye, making vision impossible for approximately five seconds, until the eye restores itself to its normal, unstimulated state. An afterimage will also be visible for a considerable time, impairing the victim's ability to aim with precision. The loud blast is meant to cause temporary loss of hearing, and also disturbs the fluid in the ear, causing loss of balance.

Now clearly that is not something our eyes have ever evolved to cope with, however equally it is not something that is impossible for them to cope with. You need to upgrade the ability of the photorecepter cells to recover from the after-effects. Not something that we could do with our current understanding of genetics but not something that is out of the question for future understanding.

Similarly the ear already has some defense mechanisms against loud noises, those mechanisms can be upgraded and made to act quicker.

Answer 3

here is a study on the current research into producing such things biologically. http://www.sciencedirect.com/science/article/pii/101113449285002C

there biggest worry is that they are still going to go blind for a second, especially with the recovery time on the photochrome. but for that level of genetic engineering you should be looking at more than a few decades, it's one thing to engineer a zygote, but an adult soldier will be much harder.

Answer 4

To build on what Cort Ammon said: Covering the eye is probably not the best option. But creating protected backup photoreceptors might work. The cells would then be modified so that they have twice as much opsins (the light sensitive proteins), half of which are locked down with another protein that only separates from the opsins after being activated by very high intensity light. The flash exhausts the normal photoreceptor and simultaneously activates the backup. Ideally the "lockdown-protein" would change to another state once exposed to a flash, for as long as the flash lasts, and only uncouple after it is no longer stimulated by intense light.

Answer 5

You might consider increasing the reaction time of your human test subjects. Animals like flies, crayfish, and squid all have significantly faster reaction times than we currently do (see https://www.quora.com/How-do-the-reaction-times-of-various-animals-compare-with-that-of-humans)

This has two advantages that I can think of right now:

• They can take evasive action before a flashbang goes off (start to turn their head away, or cover their ears, or duck behind an object).
• They will have better reflexes in a gun fight in general, especially vs non-enhanced troops.