This round eyeball is similar to a camera. A camera has a hard glass lens, and the eye also has a lens. The lens is called the lens. This lens is not as hard as the lens in a camera, but is softer. The eye can change the thickness of this lens in various ways to focus on distant and nearby objects.
Inside the eye is a membrane called the retina, which acts like the film in a camera. When the retina senses light or color, it transmits this information to the brain via nerves. This is where the sensation of seeing occurs.
In this way, the human eye is much like a camera, but it is much more sophisticated than a camera.

There are various types of diseases that can cause blindness. Corneal opacity, in which the cornea, the entrance to the eye where light enters, becomes cloudy, causing blindness. Cataracts, in which the lens becomes cloudy. Retinitis and retinal detachment, in which the retina stops accepting light.