andromedanut Posted April 7, 2023 Posted April 7, 2023 Let's say you point a laser at your eyeball.. you end up seeing where the laser is in terms of location and not seeing it where the laser hits your eye. Does this make sense? Imagine you had a blue flashlight that shined on your eye.. it hits all parts of your eye so shouldn't you see the blue taking up your whole field of vision and not justthe small area where you would see it since it's hitting all parts of your eye? This goes with looking at all objects.. if we really see because of light rays shining off objects and hitting our eyes.. this is weird to me is it weird to everyone else? I hope I'm explaining this correctly and you understand what I'm trying to say!
exchemist Posted April 7, 2023 Posted April 7, 2023 (edited) 52 minutes ago, andromedanut said: Let's say you point a laser at your eyeball.. you end up seeing where the laser is in terms of location and not seeing it where the laser hits your eye. Does this make sense? Imagine you had a blue flashlight that shined on your eye.. it hits all parts of your eye so shouldn't you see the blue taking up your whole field of vision and not justthe small area where you would see it since it's hitting all parts of your eye? This goes with looking at all objects.. if we really see because of light rays shining off objects and hitting our eyes.. this is weird to me is it weird to everyone else? I hope I'm explaining this correctly and you understand what I'm trying to say! For a start, aiming a laser at your eye is an idiotic thing to do, as it is likely to blind you. NEVER do that. Secondly, it looks as if your problem in understanding here is that you do not know some basic optics. The role of the lens in the eye is that it allows an image to be formed, whereby all rays of light from each point in an object that reach the eye, regardless of exact direction and regardless of which point of the the lens they strike, are focused onto a single point on the retina. This property of lenses results in the formation of an image of the object on the retina, rather that just an undifferentiated blob of light. In the diagram below the upright black arrow is the object. two light rays from the tip, going in different directions and hitting different parts of the lens, are shown. The lens makes these converge, to form an upside down image of the tip of the object, at a certain distance behind the lens. That is what happens in your eye. A laser is a bit special in that all its light rays are parallel. That causes the lens to focus all of them onto the same point. So a laser aimed at your eye would look like an extremely - in fact dangerously - bright single point of light. That's why it can blind you. Edited April 7, 2023 by exchemist
andromedanut Posted April 7, 2023 Author Posted April 7, 2023 I think there's a misunderstanding of what I'm trying to say.. let's say you're looking at your keyboard.. look at the letter q.. light from the q is hitting all the parts of your eye like where ypu see w,e r and t and not just where you see the q because we can see q from every angle thus telling us this but how come we only see q where the q is and not where the other letters are if light is coming from the q hitting all parts where you see.. does this make more sense?
Genady Posted April 7, 2023 Posted April 7, 2023 4 minutes ago, andromedanut said: light from the q is hitting all the parts of your eye Not exactly. The light from the q is hitting all parts of the lens in your eye, but only one spot on your eye retina. Similarly, the light from the w hits all parts of the lens but only one spot on the retina. And the latter spot is not the same as the former.
exchemist Posted April 7, 2023 Posted April 7, 2023 42 minutes ago, andromedanut said: I think there's a misunderstanding of what I'm trying to say.. let's say you're looking at your keyboard.. look at the letter q.. light from the q is hitting all the parts of your eye like where ypu see w,e r and t and not just where you see the q because we can see q from every angle thus telling us this but how come we only see q where the q is and not where the other letters are if light is coming from the q hitting all parts where you see.. does this make more sense? No. It is as @Genadysays. Suggest re-reading my post and trying to get hold of the idea of how an image is formed. What I have been trying to explain is that all the light that hits your eye from the letter Q is focused , by the lens, on just one part of your retina ONLY, where it forms the shape of a letter Q (upside down, but don't worry about that for the present). Similarly for the light coming from the other letters. You could try reading this, which explains image formation by a lens at greater length: https://www.physicsclassroom.com/class/refrn/Lesson-5/Converging-Lenses-Ray-Diagrams
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