“…The number of OPs contained in the OP complex may vary according to various factors such as the level of retinal light-adaptation (Li et al, 1991;Peachey et al, 1991;Kuze and Uji, 2005); the color of the flash and background light used for their recording (Kergoat and Lovasik, 1990); and the species under study (Wachtmeister and Dowling, 1978). The individual OPs have been shown to vary differentially under various stimulus/ recording parameters (Coupland, 1987a;Lachapelle, 1991;Tremblay and Lam, 1993;Jana´ky et al, 1996) as well as physiological Lovasik, 1990, 1992;Jana´ky et al, 1996;Kergoat and Forcier, 1996) or pathological (Coupland, 1987b;Brinchmann-Hansen et al, 1992;Lachapelle et al, 1998;Lubinski et al, 2003;Liu et al, 2006) stress factors.…”