A woman in her twenties experienced a central scotoma in her left eye while she was gazing at the visual display of a Smartphone. Her Best Corrected Visual Acuity (BCVA) the following day was 20/15 OD and 20/60 OS. A ringshaped yellowish reflex surrounding the central fovea was observed in the left eye on a fundus photograph, and the inner segment Ellipsoid and Interdigitation Zones (EZ and IZ, respectively) were defective at the foveola on Optical Coherence Tomography (OCT). Ten days later, her BCVA became 20/25 OS. Although defects in the EZ and IZ remained, the fundus abnormality became obscured. Forty days later, her BCVA returned to 20/20 OS, her fundus findings appeared normal, and both EZ and IZ demonstrated nearly normal appearances. Although transient macular damage has been reported in young Patients after prolonged gazing at a computer game display, to our knowledge, this is the first report presenting similar OCT-detectable macular damage that is likely related to Smartphone usage. Since Smartphone’s have become exclusively popular all over the world among not only adults but also younger population, ophthalmologists should be aware that macular damage can occur in Smartphone users, particularly after gazing at the display under dim background illumination. Although such cases are rare, the damage is usually transient and spontaneously recovers after reducing the duration of Smartphone usage.