Why can we see light sources ?

Learning physics and chemistry easily and freely - Science for elementary school, middle school and high school

Obviously, seeing objects is possible thanks to our eyes.
The human eye is a light receiver that converts this one in nervous signals sent to brain through of the optic nerve.The brain interprets these signals and reconstructs an image.

The term "light receiver" indicates that eye must receive the light emitted by an object so that it can be seen.
Reception of light is possible under some conditions:
- The eye must be oriented so that the light emitted by the object can penetrate its pupil.
- The object must emit enough light so that it can be detected by the eye.
- The area, between eye and observed object, must let pass light. This kind of medium is said " transparent " (as opposed to opaque which qualify a medium that doesn't allow propagation of light)

Science class

Optics lessons

Light sources

- Types of light sources
- Why can we see objects ?

Propagation of light

- Rectilinear propagation of light
- Beams of light
- Speed of light
- Light and distances

Shadows, lunar eclipses and phases of the moon

- Formation of shadows
- The Moon and eclipses

Colored lights - color of objects

- Decomposition of white light
- Colored lights
- Color of objects

Image formation - Thin lenses

- Thin converging and diverging lenses
- Image formation by thin lenses
- Vision and eyes