Macular dysfunction was studied in 7 patients recovering after surgery for a retinal detachment involving the macula. The degree of disturbed size perception (dysmetropsia) and metamorphopsia was measured in parallel with letter and grating acuity in patients during the recovery process for time periods up to 47 months following successful re-attachment. The demonstration of dysmetropsia, quantitatively assessed by a matching technique, in several patients indicate that the spatial density of the macular photoreceptors changes following detachment. In 3 patients out of 7 a longstanding micropsia was present. The degree of micropsia was not related to the degree of metamorphopsia. Subclinical/clinical macular oedema is considered to be the most probable cause for the increased separation of the macular photoreceptors. The study indicates that quantitative measurement of dysmetropsia gives valid information about receptor displacement and of unilateral subclinical macular oedema. The relations between letter acuity, grating acuity and micropsia gives certain information about the role of changed receptor separation as a cause of impaired central vision, and we found that incomplete recovery of acuity partly can be due to long-standing separation of foveal receptors.