The human eye

After the brain, the eyes are the second most complex organ in the human body. Weighing 28 grams and being made up of about 2 million parts (including 120 million rods for night vision and 8 million colour sensitive cones for day vision), the eye can distinguish 500 shades of grey and process about 36000 bits of information per hour. It will focus on 50 objects per second and contribute towards 85% of your total knowledge.  To keep the eye clean and moist, the eye blinks about 12 times a minute, which accumulates to 10 000 times a day.  Although the surrounding muscles and the eyelid need rest, the eye itself never does. Protective reflexes close the eye automatically when you sneeze or when something is about to hit it.