Questions tagged [eyes]
The discussion of the anatomy and evolution of eyes. Consider using the "vision" tag for questions regarding how the brain interprets information from the eyes.
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Eye Brain Mapping
If our eyes are separated by some kind of full proof barrier/isolation, is it possible that our brain can picture/visualize two different pictures at a time?
How the brain will function in this ...
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Eye color genetics
I am trying to find a model to link the phenotype eye color to its genotypes.
I know that there exists a simple model from Davenport, which explains {brown,blue} eyes. Further, there is an extended ...
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Is RGB diode lighting okay for the eyes?
Is a light source giving off light composed of red, green and blue lights harmful to the eyes? Does it lack any important qualities that other artificial light sources, such incandescent lamps or ...
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Why are trichromat cone cells unable to sense ultraviolet and infrared radiation?
I understand that cone cells vary in the color they sense, is this because of wavelength, frequency, something else, or a combination of the previous? I also understand that tetrachromats can see an ...
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How long can you keep sheep eyes in formaldehyde before dissecting?
We're preparing for an experiment in our classroom and my teaching partner and I are at different points in the unit. I am concerned that the experiment will be less successful because of the ...
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Is it technically possible to make someone see something when their eyes are closed?
I'm writing a little article and need any information about how human vision works and latest
technologies and discoveries around. Actually its not a professional article. Its for a group of my ...
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What is the difference between a circular and a cat's-eye (slit) pupil?
I've been to local zoo the other day and one lizard caught my attention: its pupils are circular, which, I thought, is not usual for reptiles. Turns out it is, but now I can't find any explanation on ...
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Perception of artificial light - flickering
I noticed something strange a couple of years ago. I was walking down the street at night, when it struck me that the street lights were flickering. But, when I turned to take a direct look at the ...
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HSL Lightness vs Eye sensitivity
In a monochromatic spectrum, is the human eye equally able to distinguish between lighter colors just as it is in distinguishing between darker colors? I mean is there really a linear relationship ...
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How do bats distinguish between day and night?
How do bats distinguish between day and night? Do they hunt at night - if yes, how they know that?
Are they afraid of sunlight?
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Do octopuses have better eyes than humans?
I've read that unlike humans, octopuses have eyes "designed" the "right way", i.e. with the nerve fibers behind the retina, thus getting rid of the blind spot we humans have as well as theoretically ...
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Is the eyes' movement discrete?
When tired and it was dark, I noticed that if I focused on a dim light source and moved my eyes fairly rapidly sideways, the resulting images that lingered for a short while were not smoothly blurred ...
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Eyelids interconnected?
I've seen a patient who had a Vitrectomy (eye surgery) done on a single eye manifest massive swelling on both eyelids.
That seems like having my left hand swell after punching a wall with my right ...
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What are the "stars" we see after a bump on the head?
Sorry if this might appear funny. When I close my eyes for a longer time, and suddenly open it, I see some twinkling white small circles, and when i concentrate on anyone of them it disappears, as ...
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Preferred Aspect Ratio for Human Eyes
Our eyes are spherical, our retina is circular, but still our eyes can see more in the horizontal direction than in vertical direction. Why is it so, why is the preferred aspect ratio not square?
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Screen brightness for reading in dark room [closed]
While searching online I did not find any conclusive article on whether it is good or bad for one's eyesight to read on a computer screen in a dark room. Most mention that it will cause strain that ...
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Which shades/hues of color are easiest to distinguish for humans?
I'm trying to represent data graphically and am using a variation of hue/lightness to distinguish one data point from the next. I would like to use a color that would allow me to convey most ...
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Can visual acuity be improved?
Is it possible to completely cure myopia using natural methods (i.e. not with Lasik etc.)?.
I have seen websites claiming that exercising the eyes will help improve eyesight.
Is this true?
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Why does squinting allow you to see objects more clearly?
How does squinting alllow one to see clearer pictures? What are the harmful effects?
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Does retinal detachment happen more frequently at night?
My understanding and experience is that during the night photoreceptors are less tightly coupled to the retinal pigment epithelium. Does this make it more likely for a retinal detachment to happen at ...
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Why do rod cells not recover after bleaching upon exposure to bright light?
I'm confused as to why, when exposed to bright light, rod cells cease to function.
I understand that exposure to bright light bleaches all of the rhodopsin, but...so what?
Why doesn't the bleached ...
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Why does this illusion work?
This is another image I found on Google+
All lines are absolutely straight, parallel and perpendicular but why does it appear to have a curvature?
Related: How does this illusion work?
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What negative effects can pinhole glasses have on the body?
While shopping in the local supermarket yesterday, I was surprised to find this display on one of the shelves.
I also realize that I should have taken a pamphlet with me, as well as a picture of the ...
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Are rods/cones rejuvenated periodically?
Pretty much what the title states.
Some cells/structures in the human body undergo rejuvenation periodically by flushing away older cells and growth of new ones.
E.g Skin, Blood
Does this (for want ...
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How does this illusion work?
I found this image on Google+
If you shake your head you can see a portrait of a person. Can anyone explain how the image is constructed in the brain?
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Cause of short sightedness/ far sightedness
I recently had gone for an eye test. The doctor told that short sightedness/ far sightedness is caused due to shrinking or expanding of the eye.
One thing i forgot o ask him was what causes that ...
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Is it true that newborn babies don't produce tears while crying? Why?
Well, I was just going through an article on eye, where in fun facts it was mentioned that newly born (for initial 1 to 3 months) babies do not produce tear while crying. Actually, I have found this ...
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Foveal ganglion cell density (Tay-Sachs Disease)
I’m currently reading on Tay-Sachs disease and have stumbled upon something regarding the typical “cherry red” macula symptom.
On the one hand it is mentioned that the macula is almost devoid of ...
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Why do glial cells of the retina become more abundant the closer they are to the optic nerve?
I am doing a project on expression of GFAP in the zebrafish retina. GFAP is a marker for glial cells.
I have found that the glial cells are more abundant the closer they are to the optic nerve at the ...
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Do eye muscles relax when you close your eyes?
I wonder whether the eyes muscle relax when you close them. Common knowledge told us the eyes muscle get tense when you stare at nearby object. If you close your eyes, you eye lids have 0 distance ...
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Do insects with compound eyes have depth perception?
Do insects with compound eyes have depth perception? They fly as if they do, but their eyes are so close together it seems like the image would be 2 dimensional.
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What is the eye muscle status when you stare at distant view through a glass wall?
The book said when you look at object close to you, the eye muscles contract and vice versa. I wonder what will be the status of the eye muscles when I stare at distance view (such as a mountain) ...
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When did vision evolve for the first time?
Today I wondered what the first organism to evolve vision would have been. I assume that it would have been kind of primitive and basic, but of course extremely innovative and eventually useful to a ...
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How does laser surgery correct accommodation problems?
When someone undergoes laser surgery to improve eyesight, how does it correct accommodation problems?
Why does it not help presbyopia?
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Is there a reason why human eyesight and plants make use of the same wavelength of light?
The accepted range for the wavelengths of light that the human eye can detect is roughly between 400nm and 700nm. Is it a co-incidence that these wavelengths are identical to those in the ...
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How long do your eyes need to adapt to darkness and reach full contrast?
I heard you should wait some time until your eyes adapt to darkness and are able to see smallest luminosity differences, otherwise you might overlook faint objects in the ocular. Are there any rules ...
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Why does looking at bright light trigger sneezing in some people?
Why does looking at bright light trigger sneezing in some people?
Are there any recent studies that have found a cause for this Photic sneeze reflex? The Wikipedia article only references studies ...
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