A subtly curved car mirror can eliminate the dangerous "blind spot" for drivers by increasing the field of view with minimal distortion, its inventor says.
The mirror developed by R. Andrew Hicks, a mathematics professor at Drexel University in Philadelphia, has a field of view of about 45 degrees, compared to 15 to 17 degrees of view in a flat driver's side mirror, a university release reported Thursday.
Unlike simple curved mirrors that can squash the perceived shape of objects and make straight lines appear curved, the visual distortions of shapes and straight lines are barely detectable in Hicks' mirror, it said.
Normal curved mirrors can give a wider field of view but at the cost of visual distortion and making objects appear smaller and farther away.
Hicks designed his mirror using a mathematical algorithm that precisely controls the angle of light bouncing off of the curving mirror.
"Imagine that the mirror's surface is made of many smaller mirrors turned to different angles, like a disco ball," he said. "The algorithm is a set of calculations to manipulate the direction of each face of the metaphorical disco ball so that each ray of light bouncing off the mirror shows the driver a wide, but not-too-distorted, picture of the scene behind him."
The mirror does not look like a disco ball up close, Hicks said, because tens of thousands of calculations produce a mirror that has a smooth, non-uniform curve.
U.S. regulations dictate cars coming off of the assembly line must have a flat mirror on the driver's side, and curved mirrors are allowed for cars' passenger-side mirrors only if they include the phrase "Objects in mirror are closer than they appear."
Hicks' mirror may be manufactured and sold as an aftermarket product that drivers and mechanics can install on cars after purchase.