They are equations that 'summarise' experimental findings about all things to do with electricity.

Together, they describe/allow us to predict how things to do with electricity will behave.

For example, take the famous equation F=ma.

This describes the relationship between mass, force, and acceleration. With it, we can predict how a certain mass will accelerate depending on the force we apply to it, or any other variation.

Maxwells equations are the same, but much more complex, since electricity and electrostatics are complicated.

There are three main parts to the camera and the eye:

1. the bit that lets the right light in (pupil/aperture)
2. the bit that 'collects' the light and channels it to the back (lens)
3. the bit that actually senses/ detects the light (retina/sensor/film)

The sensor part of a digital camera is actually normally much worse than the human eye. In terms of pixels, the human retina is 10 to 20 times higher resolution than a professional camera (24MP vs ~500MP)

However, the human eye has very limited lenses to collect and focus light.

Firstly, eyes have only two lenses: the cornea for main focusing, and the inner lens for fine tuning. Photography cameras tend to have more than 7 lenses.

Secondly, the human eye's lens can't change shape much, and certainly can't move. This means it has to be set for 'medium range' to allow you to see things quite close, and quite far. Camera lenses can move as much as we want them to - so we can adjust them for very far distances or very close distances fairly easily. And if we need to go even closer or farther, we can change the whole lens set for a set that is better suited to it.

The reason lenses are so important is that there is light everywhere, coming from all different angles. If we don't have a lens and pupil (or aperture) to focus the light we're interested in, and filter out what we don't want, the image will be fuzzy with mixed signals from everywhere else, regardless of how sensitive the detector inside is.