There are several methods to measure a refractive error. The 'golden standard' to prescribe spectacles is a manifest refraction (Thibos, Hong, Bradley & Applegate (2004)). This method was already described by F.C. Donders in 1864 and is performed with trial lenses and a visual acuity chart to measure the refraction error (Donders (1864)). An automated refraction is a quick routine machine based assessment, mainly used as a starting point for a manifest refraction and is based on retinoscopy (Nissman et al., (2004)).