Paying attention to the road

Human eyesight is superior among mammals. The three elements of good eyesight are stereovision, sense of three colors, and fovea centralis. Unlike cows, mice and dogs, anthropoids have flat faces, and both eyes are projected straightforward. In this arrangement, the vision formed by the eyes is narrow at less than 180 degrees, but can accurately measure the distance to an object sitting at the crossing point of the two eyes’ visibility. This is stereovision. The ancestors of primates only had color cells for sensing the colors green and blue. But color cells for sensing red are known to be added some 33 million years ago, enabling them to discern and pick ripe fruit and young and tender buds.

One especially important thing is fovea centralis. Human visual cells are not evenly dispersed on the retina, but highly concentrated at fovea centralis. For this reason, human can clearly see an object only at an angle of a mere 5.2 degrees. The eye is completely different from camera film. To see properly, one should roll his or her eyeballs and adjust the eye focus on fovea centralis. The eyes of an anthropoid are located within eye chambers. In most primates, eye holes in the skull are open to the brain, but in an anthropoid, the back of the two eye holes are closed in a globular form to form eye chambers. This is also an evolutionary apparatus designed to allow an anthropoid to fixate the eyeballs and thus prevent fovea centralis from swaying.

A truck driver caused a traffic accident that killed three female cyclists by watching DMB TV while behind the wheel. The Road Traffic Act obliges drivers to keep their eyes forward, which means “looking attentively at something.” Since human eyes have only one fovea centralis, humans cannot look at two objects at once. If one looks sideways, he or she cannot look forward. What if he watches TV at a location in the direction in which the car is moving? This is also a no-no. Due to the stereovision function of the human eye, if one looks at a DMB TV screen sitting up close, the image of an object more distant is not properly projected on the retina.

Last year, 140,000 traffic accidents occurred due to negligence in keeping eyes forward, accounting for 63 percent of all traffic accidents. In a survey by the Land, Transport and Maritime Affairs Ministry, 93 percent of motorists said watching DMB TV while driving is dangerous, but 33 percent of them said they rarely or frequently watch DMB while driving. These people can potentially cause major accidents. DMB for motorists should be designed to automatically turn off when the drive accelerates above a certain speed. This rule should be made into law and violators should be punished.

Editorial Writer Heo Seung-ho (tigera@donga.com)