The physical and chemical adjustments of the eye and visual system that reduces sensitivity to light as levels of illumination are increased.
                                                            
                                                     
                        
                                                
                        
                        
                            Process in which the sensitivity of the photoreceptor response decreases when exposed to light, so that each additional photon generates a smaller response
                                                            
                                                     
                        
                                                
                        
                        
                            the process of adjusting the eyes to relatively high levels of illumination; the pupil constricts and the cones system is operative