title: Safety of iPhone retinal photography.
abstract: BACKGROUND
  With the advancement in mobile technology, smartphone retinal photography is becoming a popular practice. However, there is limited information about the safety of the latest smartphones used for retinal photography.
  
  
  OBJECTIVE
  This study aims to determine the photobiological risk of iPhone 6 and iPhone 6 plus when used in conjunction with a 20Diopter condensing lens for retinal photography.
  
  
  METHODS
  iPhone 6 and iPhone 6 plus (Apple, Cupertino, CA) were used in this study. The geometrical setup of the study was similar to the indirect ophthalmoscopy technique. The phone was set up at one end of the bench with its flash turned on at maximal brightness; a 20 Dioptre lens was placed 15 cm away from the phone. The light that passes through the lens was measured with a spectroradiometer and an illuminance probe at the other end to determine the spectral profile, spatial irradiance, radiant power emitted by the phone's flash. Trigonometric and lens formula were applied to determine the field of view and retinal surface in order to determine the weighted retinal irradiance and weighted retinal radiant exposure.
  
  
  RESULTS
  Taking ocular transmission and the distribution of the beam's spatial irradiance into account, the weighted retinal irradiance is 1.40 mW/cm2and the weighted retinal radiant exposure is 56.25 mJ/cm2. The peak weighted foveal irradiance is 1.61 mW/cm2.
  
  
  CONCLUSIONS
  Our study concluded that the photobiological risk posed by iPhone 6 indirect ophthalmoscopy was at least 1 order of magnitude below the safety limits set by the ISO15004-2.2.
authors.affiliation: a Dunedin Hospital , Dunedin , New Zealand.
authors.forename: Sheng Chiong
authors.initials: SC
authors.lastname: Hong
authors.affiliation: a Dunedin Hospital , Dunedin , New Zealand.
authors.forename: Giles
authors.initials: G
authors.lastname: Wynn-Williams
authors.affiliation: b Gisborne Hospital , Gisborne , New Zealand.
authors.forename: Graham
authors.initials: G
authors.lastname: Wilson
mesh_terms: D006801:Humans; D009887:Ophthalmoscopy / Q000009:adverse effects; D010781:Photography / Q000379:methods*; D012160:Retina / Q000000981:diagnostic imaging*; D000068997:Smartphone / Q000706:statistics & numerical data*
keywords: Eye hazard; biohazard of smartphone light; iPhone retinal photography; retinal photography; smartphone light safety