All Questions
40
questions
15
votes
2
answers
2k
views
Eye Floaters Optics
Eye floaters are these annoying objects floating in someones eye, usually seen by someone experiencing them as squiggly lines and dots buzzing around, either dark or partially transparent (I ...
- 153
2
votes
3
answers
224
views
What is the apparent location of a real image formed by a lens? [duplicate]
Let's say I place a tennis ball 1 m in front of a plane mirror. The mirror will form a virtual image of the tennis ball, and if I look in the mirror, it appears to me that there is a tennis ball ...
- 8,343
1
vote
2
answers
164
views
How do our eyes perceive a parallel beam?
So if our eye is considered a lens, a parallel beam (sort of like collimated light from a flash light) should converge to a single point, the focal point. So does that mean our eye will see a finite ...
- 313
0
votes
1
answer
226
views
Is it correct to say that light makes things visible but light itself is invisible?
Why some books write light itself is invisible but makes things visible for us. I mean if a laser beam is passing just parallel to our eyes in a dust free environment we can't see it but the reason ...
- 1,357
1
vote
2
answers
144
views
Why rays of light from different points don't form an image?
I'm asking a clarification about this questions:
Why does an image only form where light rays coming from a single point get reflected or refracted and converge to a common point?
I want to know if ...
- 338
2
votes
2
answers
231
views
Farsightedness glasses beyond focal length
As I understand, farsightedness glasses use convex lenses to create virtual image that is farther than the object (and thus past the near point of the user). However, this only happens if the object ...
- 307
0
votes
2
answers
204
views
How do we see with glasses or contact lenses if the image formed by them occurs behind the eye?
Apologies for the poor wording of the question, I'm sure I'm gravely misunderstanding something here but not sure exactly what.
Suppose we have some point light source. We can see it because the rays ...
- 103
0
votes
0
answers
85
views
How does the human eye form an image of a certain size at a certain distance?
In looking at how geometric optics works and how an eye rebuilds an image of a certain size at a certain distance, some questions came to me:
Let's take a look at the first picture for example; the ...
- 941
2
votes
0
answers
192
views
Why are actual prescription lenses for myopia almost plano concave with the curvier face near the eye?
In a recent revision of the chapter on spherical aberrations in lenses, I found that the lens with minimum aberration will be the one in which the curvier side faces the incident ray.
This is shown in ...
- 677
0
votes
8
answers
980
views
How we can distinguish objects separately, even if light rays from them are getting mixed up in space surrounding them?
I am a high school student and I am very confused in one thing in optics (ray optics) which I think is the most basic thing but didn't find any answer on internet, before I ask let me present one ...
- 470
0
votes
1
answer
372
views
Proofs for off-axis focal lengths of a concave mirror
I am reading "Fundamentals of Optics" the 4th edition, by Francis Jenkins. The book mentions a conclusion for off-axis concave mirrors:
That is, depending on:
mirror radius of curvature $r$...
- 257
0
votes
1
answer
73
views
Question about obscura eye lens
Assume I have some contact eye lenses which I covered with black color, so they're not transparent anymore. Then I made a tiny hole at the center of each eye lens. What kind of an image will I see if ...
0
votes
1
answer
156
views
Do all objects we see emit light which then forms an image inside our eye?
Daily life we see so many objects .Often in textbooks the ray diagram for the image formation in eye is shown by showing light rays coming from the object and making an image in inner layer of eye . ...
- 512
2
votes
3
answers
1k
views
How do we perceive object distance in refraction/reflection?
Suppose we have some object, from which light rays reflect off and reach our eye. In this example, we can directly see this object, and the image is formed on our retina.
However, consider a coin kept ...
- 493
1
vote
2
answers
573
views
Why do the eyes of a person wearing glasses not look blurry if almost everything looks blurry when I wear them?
When I wear my mother's (hyperopic) glasses, almost everything appears blurry, (the reason for which was explained in this answer). What I don't understand, is why this doesn't work backwards. ...
- 3,340