We can see electromagnetic signals between wavelengths 400nm and 750nm, known as the visible light spectrum.
Objects absorb most of the wavelengths, but some light is reflected to our eyes, that is the light we see.
Light enters our eye through a lens which flips the image upside down. (see Parts of the Eye)
Our neurons then process the image unflipped.
There are a couple of disorders that can occur.
- Hyperopia is where the light focuses behind the the plane of the retina
- Myopia is where the light focuses in front of the place of the retina
