Thirteen used windshields from General Motors automobiles were randomly selected for test. Code monograms on each indicated they probably were the original equipment windshields. Photographs were made through each of the scattered light surrounding automobile headlights. Damage from windshield wiper action seemed to be related to miles of travel. Damage from hand cleaning and ice scraping operations was unrelated to age in this small sample. Pitting from small high velocity particles also showed up. On a subjective rating scale, 8 of the 13 windshields were judged to be damaged enough to cause a noticeable increase in glare, especially at night, and to warrant consideration of replacement with a new windshield. Four were judged to be unsafe for night driving.
*Submitted August 6, 1968, for publication in the August, 1969, issue of the American Journal of Optometry and Archives of American Academy of Optometry.
This study was conducted with the assistance of Mr. H. M. Alexander, Vice President, Technical Services, of the Libbey-Owens-Ford Glass Company in Toledo, Ohio.
†Optometrist, Ph.D., Member of Faculty. Fellow, American Academy of Optometry.
© 1969 American Academy of Optometry