Light and Vision: Photon Direction

In summary, the angle at which light enters the eye is what allows the eye to differentiate between different objects.
  • #1
clalburn1420
12
0
How is it that light disperses from a point source (like a pinhole w/ a light shining through). From my understanding, photons disperses in all directions at all angles. So than how is it that an eye can differentiate that point from all the other points light around it (say there was another pin hole in a different area of the field of view). Would not the complete dispersal from one point of light hit every photoreceptor cell? And if so, how would it differentiate that stimulus from another point of light?
Thanks very much.
 
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  • #2
That's what the lens of the eye is for. It converges the light from each point source to a single point on the retina.
 
  • #3
clalburn1420 said:
How is it that light disperses from a point source (like a pinhole w/ a light shining through). From my understanding, photons disperses in all directions at all angles. So than how is it that an eye can differentiate that point from all the other points light around it (say there was another pin hole in a different area of the field of view). Would not the complete dispersal from one point of light hit every photoreceptor cell? And if so, how would it differentiate that stimulus from another point of light?
Thanks very much.

It is the angle of the rays coming in to your eye that identifies the direction to you.

Think about what you're seeing right now. There's a light ray coming from a window in your peripheral vision. It impinges on your eye near the edge of your cornea and directed into your pupil where it impinges on your retina way over near the edge. A stimulus received at that point on your retina appears in your vision as a source of light in your preipheral vision.
 
  • #4
Still not sure i understand. Let me try illustrating my understanding, and then correct me one how terribly misinformed i am.

In the attachment i did a rough representation of what I'm talking about. If two points of emitting light are next to each other and near the eye, won't their photons be crossing paths, eventually striking same receptors?
I mean, one point of light does not transmit through the eye in only one direction/angle, does it?
 

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  • #5
clalburn1420 said:
I mean, one point of light does not transmit through the eye in only one direction/angle, does it?
The purpose of a lens component is that it takes divergent rays coming from a single distant source and focusses them at a point.

See diagram.
 

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  • #6
I think i get it. Thats pretty amazing. Thanks very much!
 

1. What is a photon and how does it relate to light?

A photon is a tiny packet of energy that makes up electromagnetic radiation, including visible light. It is the basic unit of light and is responsible for carrying light and other forms of electromagnetic radiation through space.

2. How does the direction of photons influence our vision?

The direction of photons is crucial for our vision as it determines the path of light entering our eyes. The photons that enter our eyes from different angles and directions are focused by the lens onto the retina, where they stimulate the cells responsible for vision. Therefore, the direction of photons plays a significant role in determining what we see.

3. How do photons travel through space?

Photons travel through space as both particles and waves. They move at the speed of light, which is 299,792,458 meters per second. As they travel, they can interact with matter, such as bouncing off surfaces or passing through transparent materials like air and water.

4. Can photons change direction?

Yes, photons can change direction through processes such as reflection, refraction, and diffraction. For example, when light hits a mirror, it bounces off in a different direction. When light travels through a prism, it is refracted and changes direction based on its wavelength. These changes in direction are essential for forming images and allowing us to see the world around us.

5. How does the color of light relate to photon direction?

The color of light is determined by the wavelength of photons. Different colors correspond to different wavelengths, which can affect how light behaves and changes direction. For example, red light has a longer wavelength than blue light, so it is less likely to bend or diffract. This is why red light is often used for long-distance communication, such as in traffic signals.

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