Tagged Questions
1
vote
1answer
54 views
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 ...
4
votes
3answers
70 views
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 ...
6
votes
2answers
96 views
What is the difference between a circular and a cat's-eye 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 ...
2
votes
0answers
19 views
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 ...
8
votes
1answer
116 views
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 ...
6
votes
2answers
794 views
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 ...
2
votes
1answer
97 views
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?
4
votes
1answer
122 views
Why does squinting allow you to see clearer objects?
How does squinting alllow one to see clearer pictures? What are the harmful effects?
1
vote
1answer
31 views
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 ...
8
votes
1answer
221 views
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?
2
votes
1answer
616 views
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 ...
1
vote
0answers
111 views
How do optical illusions work? [closed]
Hello fellow investigators
I have two questions about optical illusions
1) A photo mosaic is something like this http://i.stack.imgur.com/Pzplp.png
What are the optical principles behind our eye ...
4
votes
1answer
660 views
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?
11
votes
2answers
286 views
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 ...
37
votes
3answers
570 views
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 ...
