[Case of unilateral impairment of short-wavelength sensitive cone with sudden onset]

Compare to either the middle or the long cones, short cones (S-cone) are easily damaged.A 62 year-old men complained of acute tritan OS. The corrected visual acuity was 1.2 OU. Routine ocular examinations showed no remarkable abnormalities, but we detected impaired responses using S-cone ERG and blue-on-yellow perimetry OS. We diagnosed this case as acute damage of the blue cone.S-cone damage can be determined by electro-physiological and psychophysical examinations in cases of unilateral color abnormality.