Three cases of morning glory syndrome are described and some new electrofunctional and tomodensitometric findings are reported. The amplitude of the waves of the electroretinogram is reduced and correlates with the extension of the retinal changes. The visually evoked potentials elicited with bright flashes have normal latencies but generally subnormal amplitudes. The amplitude of the potentials probably depends on the degree of involvement of the optic nerve. The computerised tomography performed in one patient disclosed undescribed changes in the retrobulbar optic nerve.