Even when you look at the pen in your hand for just a few seconds, hundreds of billions of processes take place in your eye. Light passes through its cornea and pupil and then the lens, where light-sensitive cells convert it into electrical signals to be transmitted to the nerve endings as impulses. The image reaching the retina is reversed and upside down, and yet the brain can interpret it and provide a normal image by collecting the separate images from both eyes, identifying all of the object’s features, and combining the images from both eyes into a single picture. It also determines the object’s nature, color, and distance. The eyes do all of this in as little as a tenth of a second.
The same processes take place in the brain whether you look at a tiny dot or a large ship, and the resulting image forms in a 1 mm (0.0393 in) point. You can never be sure that the pen in your hand is close to you or that a far-off ship is larger than a pencil, for the size of the place where these images form is exactly the same. Yet there is a sense of distance in everything you look at, for how else could you so easily stretch out your hand to pick up a glass? Allah, Who created this flawless organ, has equipped it with unimaginably fine detail and enabled the brain see an object where it is and in full detail. The extraordinarily complex human eye is just one of His sublime works.
No human technology can duplicate such feats. Constant research is being carried out to unravel how the eye can do such incredible things, and scientists are attempting to understand just how it shows us a brightly colored world. Of course, neither the eye, which is just a few centimeters in size, nor the millimeter-sized region in which the image forms have the power to form a colored world. It is the soul that sees all of the matter existing on the outside and that reinterprets this inside the brain. Allah, the Almighty, enables people to see, perceive, and sense by breathing His own spirit into them at birth and makes these things dependent upon extraordinary conditions. The image created, the astonishing eyes that perceive it, and the countless systems involved in all of this exist only because Allah so wills it.