similarities between your eye and the camera

Both the human eye and a camera use something called a lens. In fact, they both use the same type of lens - a converging lens. Converging lenses are like the ones in magnifying glasses - they work to make an image look bigger. This is why you can see the details in something even if it’s on the other side of the room. One thing about lenses is that they can only focus on things that are the same distance away from them. This is why your eyes can focus on things that are close to you or far from you; just not at the same time. Cameras are the same way - you can only focus them on things that are the same distance away. In the camera, the lens focuses the light onto a piece of film. The film has chemicals in it that basically trap the image on it, making it permanent. Instead of film, your eye uses something called a ’retina.’ The retina has lots of little tiny things called ’rods’ and ’cones’ all over it. These are basically tiny antennae that tell your brain about the light that hits them. The rods tell your brain if there’s light in a certain spot or not (a bit like a black and white photo) and the cones tell your brain what color the light is. There is one spot on the retina, though, that has no antennae at all. This is the spot where the nerve leaves your eye to go to your brain. At this spot, you can’t see anything at all - it’s called your ’blind spot.’ This is one of the reasons that you have two eyes; what you can’t see with one eye you can see with the other. Unlike your eyes, cameras have no blind spot, so they only need to have one lens. Another important thing about seeing light is that you have to be able to control how much light gets in... otherwise, you couldn’t see things in a brightly-lit room because you’d be overwhelmed by how much light there is. Your eye controls how much light gets in by changing the size of the pupil - the dark spot in the center of your eye. The more light there is, the smaller your pupil becomes, and the less light gets in. Many (but not all) cameras also can adjust to let different amounts of light in. This way, your outdoor pictures don’t look washed out and your indoor pictures don’t look too dark.