van Toi V, Grounauer P A
Klin Monbl Augenheilkd. 1980 Apr;176(4):530-2. doi: 10.1055/s-2008-1057494.
In order to avoid electrical interference and the noice caused by a gas discharge tube (flash), the authors have developed a stimulator using mechanical flash as light modulator for ERG and PEV. Flash duration is 2 ms regardless of frequency. This apparatus is now on the market.