Objective To observe the bioeffects of HPM on animal retina

and to provide biological basis for precautions against the HPM.Method The animals were divided into two groups randomly

irradiated for 10 min and 20 min respectively.Examination by thermometer

funduscope and electroretinograms（ERG）were carried out at different time points to study the effects of HPM on retina function.Results The body temperature

blood vessel of rat eyeground and b-wave amplitude of ERG showed temporary and slightly changes immediately after HPM exposure

which went natural after 1-3 days.There were no significant differences（P>0.05）in the temperature and amplitude of b-wave between the two groups.Conclusion Under a given condition

retinal functional change is after HPM exposure at single irradiation

which may be a body stress response

contributing to reparation after damage

and serves as an important early indication of damage.