Questions tagged [vision]
Physical processes involved when seeing, and comparisons between with other light detection systems. Includes questions about the eye, optical nerve, brain, corrective lenses, etc.
616 questions
-3 votes
2 answers
277 views
Can our eyes see virtual objects?
Note that I am not talking about virtual images. Can our eyes see virtual objects? If yes, then virtual objects at a specific distance range can be seen or at all distances? I was learning about using ...
- 494
9 votes
1 answer
2k views
Why do I see 3D effect on red/blue image on a dark background?
I am myopic. When I wear my glasses (ordinary nearsighted eyeglasses, not special 3D glasses, not red/blue glasses), I feel a strong 3D effect when seeing this image below, the red is "in the ...
- 513
0 votes
0 answers
150 views
Why do distant objects appear blurry in magnifying lens but not in spectacles(for farsighted people)?
Assumption for eye glasses: If we try to see objects from a converging lens(eye glasses) located just in front of the eye, that are farther than the focus(between f and 2f) of the eye glasses, we can ...
- 494
-1 votes
1 answer
138 views
Can a person read with spectacles a book which is located farther than its focus?
I was solving a question but I couldn't understand a concept of it. A professor reads a greeting card received on his 50th birthday with +2.5 D glasses keeping the card 25 cm away. Ten years later, ...
- 494
3 votes
1 answer
166 views
Vision with pupils obstructed at the center
Assume that a person puts special contact lenses on both of his eyes, centered at the pupils, such that each of those contact lenses have an opaque center with diameter 1mm, while the typical pupil ...
- 185
-1 votes
2 answers
169 views
How we see objects?
Does irregular (diffused) reflection cause us to see objects? If so, why? Diffused reflection means that the surface is rough and hence rays are irregularly dispersed. If that is the case, then how do ...
- 29
1 vote
1 answer
143 views
What type of lens do I need and why?
I would like to be able to focus with my eye on something that is closer than I can normally focus without optics. I wanna put my eye up to a hole in a box and be able to see the thing in the box ...
- 111
1 vote
3 answers
170 views
Why do far objects on a mirror require a different focus despite its image being closeup?
Apologies if this question is already answered - I am not sure what this phenomenon is called so have not been able to search this topic thoroughly. Say on a laptop screen, you have content displaying ...
- 113
46 votes
13 answers
10k views
Why aren't we bumping into objects outside of the visible range?
Apologies if this is too simple of a question for this site. My physics education stopped at the undergrad level. My 12 year old nephew asked me a question and I couldn't give him an answer. He asked, ...
- 569
0 votes
1 answer
145 views
Would a straight bridge seem bent to the human eye?
I'm not really sure whether this is more biology or physics, probably it's relevant. Consider a perfectly straight bridge (straight as a light ray) tangent to the earth surface at some point. We know ...
- 351
5 votes
1 answer
271 views
Making sense of positive and negative systems for eyeglass prescriptions
Let's say we have a pair of single vision eyeglasses and we're going to convert the "plus" system to the "minus" system. That involves 3 steps: Add the Sph and Cyl to get a new ...
- 51
2 votes
8 answers
3k views
Why can't we see individual air molecules?
I always wonder, as we all know, we see the sky as blue because the air molecules scatter MOST of the light in blue range, but why can't we see individual air molecules in the atmosphere (or just ...
-1 votes
1 answer
178 views
Can every color between red and green be made using monochromatic light? [duplicate]
Is it true that every color between red and green, can be made using monochromatic light. I think is should be true according to the visible spectrum. I may only need to increase or decrease the ...
-3 votes
2 answers
248 views
Why can colours like RGB $(168, 151, 80)$ be seen by humans?
Is it true that we can only see colors that lie in the visible spectrum? If yes, then why can colors like RGB $(168, 151, 80)$ be seen by humans? Let us suppose that we are at the extremely red part ...
- 111
0 votes
0 answers
98 views
Can the eye lens not produce a virtual image when the object is between Focus and Optical Centre?
My teacher dismissed the question saying it is not possible for the eye to do so simply because we didn't know the focal length of the eye. That confused me. The focal length can vary, sure. When we ...
- 438