Volume 5, Number 6 November/December 1997
New Shades Help Drivers and Pilots
modification to a filter NASA engineers already developed for current use with agricultural goggles may make skies and roads safer by helping daytime pilots and drivers to see better.
A new sunglass filter, designed by Portland, Oregon company Optical Sales Corp., was adapted from a filter originally developed to help farmers identify diseased plants by enhancing the human eye's capacity to detect other colors in the visible spectrum by blocking yellow and green light during daylight hours.
The original filter, a low-cost, brownish, plastic material called the passive chlorophyll detector, was developed in 1991 by Dr. Leonard Haslim of NASA's Ames Research Center, Moffett Field, California.
"If we diminish or block a lot of the yellow-green light that the eye normally sees, suddenly the other colors stand out in much greater relief. This lets us see colors much more clearly, like we see them at the movies," Haslim said.
According to Haslim, stress in plants tends to be camouflaged by the plant's natural chlorophyll. As a result, many plant diseases cause irreversible damage by the time they become visibly evident. In the past, it was necessary to have highly trained professionals examine plants in order to determine signs of stress in the early stages. Haslim said that he developed his filter to address that need.
"Now, farmers themselves can use goggles equipped with the special filter to locate diseased or stressed plants,'' said Haslim. "Sick leaves that appear just a bit yellow in normal light show up as a much brighter yellow when viewed through the filter. Conversely, healthy leaves appear as a vivid green," Haslim said. The sunglass adaptation with the modified filter was first made commercially available in early 1997.
For more information, contact Dr. Leonard Haslim at Ames Research Center.
Please mention you read about it in Innovation.
Special brown sunglass filters,