Since the peripheral refractive errors seem to have some important in the development of foveal myopia, it is important to measure them in children when they start to develop myopia. There is no easy and convenient technology available at present. Juan extends our standard human photorefraction to measure over a wide range of visual angels. It is planned to use a mirror for scanning (although the path of this mirror is quite complicated).

Juan has already gathered some preliminary data from members of the laboratory (example Figure 1). Interestingly, the refraction does not change very smoothly across the visual field but rather shows some "bumps". It is quite interesting to find out whether they are really present in the fundus of the eye, or whether they trace back to local changes in reflectivity or the Stiles-Crawford effect. At lot can be learned about the tricks and pitfalls of photorefraction.