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30 votes
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Are humans more adapted to "light mode" or "dark mode"?

A question that requires quite a lot of guts to ask on this site :) Nonetheless, and risking sparking a debate, there are a few arguments that spring to (my!) mind that can support the notion that we ...
AliceD's user avatar
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19 votes

What are the floating translucent little objects called in the field of view?

I think you are talking about floaters (a.k.a. eye floaters or flying flies). You may want to have a look at this english.SE post in case you were not talking about floaters. Floaters are deposits ...
Remi.b's user avatar
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19 votes
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How deep under water can humans open their naked eyes without damaging them?

Crushing damage from pressure occurs due to pressure differences. Imagine you have a rigid container. If you have equal gas pressure inside and outside, the pressure acts on just the walls and the ...
Bryan Krause's user avatar
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13 votes

How deep under water can humans open their naked eyes without damaging them?

Goggles do not, cannot, protect eyes from pressure. The pressure on both sides of goggles should be nominally the same. In fact, divers tend to use a mask, which communicates with the nose, to be able ...
Neil_UK's user avatar
  • 231
12 votes

Why do I see different hues of colors between each of my eyes?

This is an interesting phenomenon which I have been aware of for several years, but I haven't yet come across any official description of it or explanation for it. Nonetheless, the phenomenon is easy ...
Gwen's user avatar
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11 votes
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What is the rest state for eyelids - Open or Closed?

This depends to some extent on how you define "resting state" (it matters). Innervation of the eye occurs in the brainstem and upper spinal column, so is, like most brainstem functions, on autopilot ...
anongoodnurse's user avatar
10 votes
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Can "red" cone cells actually see much red light?

This is a good question. The first thing to note is that human colour vision is very complex and still poorly understood. If you visit the wikipedia page on RGB, you will find that this correctly ...
Anon's user avatar
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10 votes

Are humans more adapted to "light mode" or "dark mode"?

From experiments it seems you should better use dark mode if you want to prevent myopia: Using optical coherence tomography (OCT) in young human subjects, we found that the choroid, the heavily ...
asmaier's user avatar
  • 201
9 votes

Do insects with compound eyes have depth perception?

Short Answer: Yes. Nityananda et al. (2018) confirmed a novel form of stereo vision by putting tiny colored glasses on praying mantises. (Newcastle University, England) [source] Long Answer ...
theforestecologist's user avatar
9 votes
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Can a color-blind person see color with filter glasses?

Short answer Optical filters can optimize color contrast, but never restore color blindness. Filters remove colors, they can never add something. However, glasses like this can prove helpful for ...
AliceD's user avatar
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9 votes
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How do our eyes detect light at different frequencies?

Short answer Action potentials generated to different colors are indeed similar throughout the nervous system and do not encode color as such. Instead, the different color- sensitive cells in the ...
AliceD's user avatar
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9 votes

If one of eyes is blind, can that eye still feel pain?

Blindness can be due to a damage of the lens, retina, optic nerve or the visual area at the occipital lobe of the brain, for example. Sensitivity of the eye cornea is enabled by a different nerve - ...
Jan's user avatar
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9 votes

How deep under water can humans open their naked eyes without damaging them?

Currently the record for the deepest dive wearing scuba equipment is 332.35m. The descent took only 15 minutes while the ascent lasted 13 hours 35 minutes. Liquids do not compress, so the sinuses, ...
bandybabboon's user avatar
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8 votes
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Why can myopic eyes focus on nearby objects, but not on distant ones?

There are four common refractive errors, namely nearsightedness (myopia), farsightedness (hyperopia), astigmatism (Fig. 1) and presbyopia. Fig. 1. Refractive errors. source: Excimer Ophthalmologic ...
AliceD's user avatar
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8 votes
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Why can't we half-close our eyes?

The motion of the eyelid is driven by the levator palpebrae superioris, i.e. elevating muscle of upper eyelid, and it can be positioned to the intermediate, half-closed positions. At least I can do it....
LuboŇ° Motl's user avatar
8 votes
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How are colors outside the standard RGB color scheme perceived?

This question is both biology and physics I think (I guess it's biophysics! :) so I feel it's worth answering here. First, we must recognize the difference between wavelength, which is just a ...
Roland's user avatar
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8 votes
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Can frogs see clearly under and above water?

Short answer Frogs are nearsighted on land and farsighted under water. Background Frogs are reported to be nearsighted on land, but farsighted underwater (source: Chegg Study). Nearsightedness (...
AliceD's user avatar
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8 votes

Cerebral activity during exposure to non - visible light

Vision is based on a protein interaction with a molecule called retinal from vitamin A. Wavelengths of light in the visual range cause a photoisomerization of retinal (a cis- to trans- change), which ...
Bryan Krause's user avatar
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8 votes

Do animals with their eyes ~180 degrees apart have depth perception?

Worth noting, even you can perceive depth with one eye closed if you slide your head left and right. It's the same reason we can have 3d gifs that just rely on sliding the camera. Look up stereoscopic ...
Alex Rose's user avatar
8 votes
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Comparion between machine vision & human vision

This is a potentially very very broad question, but I'll try to provide a simple answer that addresses the biggest misconceptions. First of all, animal vision (and brains more generally) is massively ...
Bryan Krause's user avatar
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7 votes
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Do other animals suffer from myopia or hypermetropia?

do they have such eye defects? Yes, eye defect is not specific to humans of course. Cases of eye defect are very common in animals. It is most often witnessed in domestic animals and they are the ...
Remi.b's user avatar
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7 votes

Are humans more adapted to "light mode" or "dark mode"?

Both. More specifically, we're a kitbashed light-mode version of a primarily dark-mode group of animals. Mammals famously have terrible color vision, most mammals are dichromats (red color-blind) ...
user2352714's user avatar
7 votes
Accepted

How much light can pass through the human eyelid?

Short answer About 0.79% of the light gets through on average, but there is variability across wavelengths and individuals. (variability between individuals seems to be correlated with density of ...
theforestecologist's user avatar
7 votes
Accepted

Why does there have to be two muscles to control the size of the pupil?

Short answer Agonist / antagonist muscle pairing in the form of the sphincter and dilator muscles in the iris allow for quick and powerful movements of both the constriction and the dilatory response. ...
AliceD's user avatar
  • 52.5k
6 votes

What are the floating translucent little objects called in the field of view?

Are you referring to the "worms or strings/dots swimming on the eye/vision"-phenomenon? These are also called "eye floaters" and quite common. According to IFLscience: http://www.iflscience.com/...
storbror's user avatar
  • 171
6 votes
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Why does a non-functional retinoblastoma protein cause tumours in the cells of the retina specifically?

From Wikipedia: The retinoblastoma protein ... is a tumor suppressor protein that is dysfunctional in several major cancers So, although it's commonly associated with retinoblastoma, it's not ...
Bryan Krause's user avatar
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5 votes
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What is the smallest difference in light wavelength that the human eye can detect?

The eye really on can sense 3 colors, or to be more precise it only has three types color sensitive each of which detects a large range of wavelengths with no way to distinguish between them within ...
John's user avatar
  • 14.7k
5 votes

What is the smallest difference in light wavelength that the human eye can detect?

Is there a lower limit to the difference in wavelength (colour) our eyes can detect? The average human can detect differences in color as low a 1 nm depending on color subject to: minimum spot size -...
Rob's user avatar
  • 403
5 votes
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How do S and L cone cells sense colors like deep blue and red beyond their peak?

The answer is actually present in your chart: color perception depends on the ratios of activations of different photoreceptors. For example, as you go "more red" from 575, the responses of the Green ...
Bryan Krause's user avatar
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