title: Optical quality and impact resistance comparisons of 2 football helmet faceshields.
abstract: BACKGROUND
  Currently there is no standard that specifically addresses the optical and impact performance of football protective faceshields. This study compared the impact resistance and optical quality between 2 popular football faceshields. Testing was performed only on new faceshields.
  
  
  METHODS
  To test impact resistance, baseballs were propelled at the faceshields with velocities up to 66.4 m/sec. Structural integrity was evaluated after each impact. Ten visors from each of 2 companies underwent a single impact at various velocities. Two visors from each company were impacted 3 times to evaluate the effects of repeated blows. Additional visors were conditioned to -10 degrees C and impacted once. Additionally, prismatic power, refractive power, haze, visible light, and ultraviolet (UV) transmittance, and optical distortion were measured to evaluate optical quality. All testing was done with faceshields mounted to facemask and, when appropriate, to a helmet.
  
  
  RESULTS
  None of these new faceshields fractured even with impact velocities up to 66.4 m/sec. With regard to optical quality, both protectors met the optical requirements for the standards of faceshields for selected sports (ASTM F803-2003).
  
  
  CONCLUSIONS
  Both faceshields tested should protect football players from anticipated impacts while providing adequate optical quality for satisfactory visual performance.
authors.affiliation: The Ohio State University Department of Ophthalmology, Columbus, Ohio, USA.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Baker
authors.forename: Aaron
authors.initials: A
authors.lastname: Zimmerman
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Grzybowski
authors.forename: William R
authors.initials: WR
authors.lastname: McLaughlin
authors.forename: Steven E
authors.initials: SE
authors.lastname: Katz
authors.forename: Dale B
authors.initials: DB
authors.lastname: Pfriem
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Good
mesh_terms: D006259:Craniocerebral Trauma / Q000517:prevention & control*; D004867:Equipment Design; D005131:Eye Injuries / Q000517:prevention & control*; D005135:Eye Protective Devices / Q000592:standards*; D005538:Football / Q000293:injuries*; D006260:Head Protective Devices / Q000592:standards*; D006801:Humans; D055095:Optics and Photonics