Your Multipurpose Eye
Scientists have learned that the eye is a multipurpose organ. They have long tried to figure out how our internal biological clock is set. This amazing clock is located in the brain and follows a period of almost exactly a day. It controls many of the body's rhythms, so it's important that it is properly set.
Scientists do know that the clock is set by light. They also know that your clock is not set by the rods and cones in your eye that see color and images. They had conclusively shown that the eye's rods and cones have nothing to do with setting the clock. Several years ago, researchers bred mice whose eyes lacked rods and cones. As they shifted light periods, the mice still adjusted their biological clocks to the new periods. Now researchers are convinced they have found how our eyes adjust our biological clock after studying, of all things, the African horned frog. While studying the frog, scientists discovered a photoreceptor called melanopsin. This photoreceptor is found in the skin, eyes and brain of the frogs. They then decided to test for melanopsin in our eyes. They discovered that a form of the photoreceptor is produced in the inner retina of our eyes. The rods and cones of our eyes are located on the outer retina. The human eye, and those of mammals, is a multi-purpose organ!
The intricate and precise ways in which we have been made increasingly glorify our Creator as we learn more about how we have been made. Surely it takes more faith to believe that such an elegant system as our biological clocks evolved by chance.