Near ultraviolet radiation elicits visual evoked potentials in children

Objective: Ultraviolet radiation can be transmitted through the ocular media, as well as stimulate the retina, in some invertebrate, vertebrate and mammalian species. This study sought to determine if near ultraviolet radiation (UV-A) can elicit visual evoked potentials (VEPs) in young humans. Methods: VEP responses to 10 nm half-peak bandwidths of 340, 360 and 500 nm stimuli were measured in 8 children aged 7-10 years. Each VEP was based on an averaged response to 200 flashes and was recorded using a sensitivity of 250 μV (full scale) with the International 10-20 electrode placements F(z), O₁ O(z), O₂, and A₁. Peak latencies (ms) were measured for the second negative peak, N₂, third positive peak, P₃, and third negative peak, N₃. The amplitude (μV) between N₂ and P₃ was also measured. Results: Each Child demonstrated a VEP response to both visible and UV-A stimuli. Most VEP parameters relative tO the 340 and 360 nm stimuli (P <0.05 to P <0.001) were significantly different from the VEP responses to the 500 nm stimulus. Conclusion: The results indicate that the near ultraviolet stimuli were indeed visible to the young human eye.