A 39-year-old hyperopic male was referred for laser refractive treatment. In the course of the pre-operative evaluation he complained of a recent deterioration of vision. The suspicion of unilateral central serous chorioretinopathy (CSCR) was confirmed by contrast sensitivity testing and by ocular fundus examination. Contrast sensitivity (CS) for six spatial frequencies (1, 2, 4, 8, 12 and 16 c/deg) was evaluated using Gabor patches of gratings projected on a high-resolution display by means of a stimulus generator card. Although VA remained unaltered, the pattern of contrast sensitivity function varied at different stages of CSCR: during the acute stage, performance at all spatial frequencies was depressed, while at two-month follow up, intermediate and high spatial frequencies were mainly affected. It is concluded that the level of visual deficit in CSCR cannot be evaluated by measuring visual acuity. History and contrast sensitivity can play a central role in setting the correct diagnosis and characterising its stage.