|Title||IMPACT RESISTANCE AND OPTICAL QUALITY OF FOOTBALL HELMET VISORS; OAKLEY VS. NIKE|
|Author, Co-Author||Aaron Zimmerman, Gregory Good, Kathy Baker, Randy Mclaughlin|
|Abstract|| PURPOSE: Eye safety shields are receiving more use in organized football. This study was proposed to compare the impact resistance and optical quality between Oakley and Nike football helmet visors.
METHODS: Baseballs were propelled at properly mounted helmet visors at velocities up to 140mph. Structural integrity was evaluated following the impact. A baseball was chosen as a comparison to the toe of a shoe that potentially could kick the visor. Ten visors from each company were tested at various velocities. Two visors from each company were then impacted 3 times at maximum velocity to evaluate the effects of repeated blows. Three additional visors from each company were conditioned to -10 C and impacted once. Prism, refractive power, haze, transmittance, UV absorption, and optical distortion were measured on 3 brand new visors from each company. All testing was done with visors mounted to a Riddell VSR-4 helmet and a Riddell Z-2EG face mask. Samples were randomly selected from the quantity provided.
RESULTS: No shields fractured even with impact velocities up to 140 mph or with multiple impacts. After impact, striae were visible in the plastic material. These striae were more prominent on the shields hit at higher velocities, with repeated blows, and after cold conditioning. The striae were more prominent in the Nike visors. In regards to optical quality, the shields were similar for refractive error, transmittance, and UV absorption. Both protectors met the optical requirements of hockey faceshields.
CONCLUSIONS: Both the Oakley and the Nike visors withstood high impact velocities. Both will protect players from high energy impacts. Following impact, the Nike visor had more visible stress lines near the fasteners that ran vertically across the length of the visor.
ADDITIONAL COMMENTS: This study was conducted with assistance from The Ohio State University Department of Ophthalmology.
|Affiliation of Co-Authors||The Ohio State University, College of Optometry, The Ohio State University, College of Optometry, The Ohio State University, College of Optometry|