Reduced visual discrimination in cochlear implant users.

The aim of the study was to investigate low-level visual function in cochlear implant users. Spatial frequency discrimination was assessed in 16 adults with normal hearing and 18 adults with profound deafness who had a cochlear implant. Thresholds were measured with sinusoidal gratings using a two-alternative temporal forced-choice procedure combined with an adaptive staircase. Cochlear implant users had significantly poorer spatial frequency discrimination compared with normal hearing participants. Therefore, auditory privation leads to substantial changes in this particular visual function and these changes remain even after the restoration of hearing with a cochlear implant.