Pattern electroretinograms and visual evoked potentials (VEP) were investigated in response to reversal checker-board patterns with different sizes of checks in 13 adolescents with monosymptomatic optic neuritis in acute period and in the course of convalescence 1-2 and 12-36 months after the disease onset. All the children underwent computer tomography of the orbit and brain. The results allowed identification of high and low multiple sclerosis risk groups. The high risk can be proved by a progressive increase of VEP latency 1-2 months after the disease onset and its significant advance in later period of optic neuritis. Normal VEP latency in late optic neuritis shows a low degree of its development.