This paper is an attempt to unify various approaches to the assessment of acute radiation injury of the organ of vision. The development of cataracts was studied on mice subjected to local irradiation of the head at doses: 7, 10, 12, 15, 20 and 25 Gy. A clinical picture of radiation injury of the eye at different x-ray doses at different stages was established during ophthalmological examination using a manual electro-ophthalmoscope (X5). A method of the quantitative assessment of radiation injury of the mouse eye at different radiation doses was proposed using the light transmission factor tau; its experimental value was obtained, values for different clinical stages of cataracts were established. The time course of the development of radiation cataracts in mice subjected to x-ray irradiation in a wide spectrum of doses, was observed; clinical features of the process were revealed. Dose fractionation under the above conditions did not make a protective effect on the lens. Dependence of a degree of lens injury on irradiation dose obtained owing to the use of the light transmission factor tau, was described with the following equation: (formula; see text)