title: Optical correction reduces simulator sickness in a driving environment.
abstract: OBJECTIVE
  We propose and test a method to reduce simulator sickness.
  
  
  BACKGROUND
  Prolonged work in driving simulators often leads to nausea and other symptoms summarized as simulator sickness. Visual/vestibular mismatches are a frequently addressed cause; we investigate another possibility, mismatch between actual distance to a screen and depicted distances in the simulator's graphics.
  
  
  METHODS
  Drivers negotiated a figure-8 course in a photorealistic simulator. They reported discomfort and vection every 10 minutes up to 40 min. A correction group wore optometric test frames with + 1.75 diopter lenses and prisms to converge parallel lines of sight on a screen 56 cm from the driver's eyes, preserving the normal accommodative convergence-to-accommodation (AC/A) ratio. A control group wore neutral lenses in the same test frames. In other experiments head tilt simulated vestibular experience on curves.
  
  
  RESULTS
  The optical correction significantly reduced simulator sickness measured on a 10-point discomfort scale, where I is no problem and 10 is about to vomit. Vection ratings were similar for correction and control groups. Some drivers failed to complete the course because of high discomfort ratings, crashes, or other causes. Head tilt in the direction opposite each curve while wearing the correction did not affect discomfort, while tilt in the same direction as each curve made simulator sickness worse.
  
  
  CONCLUSIONS
  Optical corrections can significantly reduce simulator sickness, though they do not eliminate it. Head tilt while driving is not recommended. Application: Simple optical corrections in spectacle frames, easily purchased at any optical facility, should be used in screen-based driving simulators. Strength of the correction depends on distance from the driver to the screen.
authors.forename: Bruce
authors.initials: B
authors.lastname: Bridgeman
authors.forename: Sabine
authors.initials: S
authors.lastname: Blaesi
authors.forename: Richard
authors.initials: R
authors.lastname: Campusano
mesh_terms: D000293:Adolescent; D001334:Automobile Driving; D003198:Computer Simulation; D005139:Eyeglasses; D006801:Humans; D009041:Motion Sickness / Q000209:etiology / Q000517:prevention & control*; D010775:Photic Stimulation / Q000009:adverse effects*; D014584:User-Computer Interface; D055815:Young Adult