Human intervention and application of electrical energy in everyday life have led to the fact that magnetic fields are considered as one of the constituents of the environment. These fields have harmful effects on biological system. Therefor the aim of this study is to investigate the effects of magnetic field on retina of rat's eye. Also, some biophysical properties of hemoglobin for group of rats exposed to different magnetic fields were detected. Forty- eight mature rats weighting (150 – 180 g) were exposed to magnetic fields in the range from 120 Gauss to 160 Gauss. Electroretinogram of all the retinas was recorded and the retina collected from rat's eye and tested through Fourier transform infrared spectroscopy and DNA fragmentation. Then testing the effect of magnetic field on hemoglobin by measuring viscosity and conductivity. The data indicate that there is no change in all the measured parameters of retina and blood after exposure to 120 and 130 Gauss. Furthermore, there was a decline in visual function and increase in DNA fragmentation by increasing the exposure dose up to 160 Gauss. The results also showed significant increase (p≤0.001) in both relative viscosity and electrical conductivity of blood after exposure to 130 Gauss and this increase continue till exposure of rats to 160 Gauss. The present results suggest that the magnetic field exposure may induce ROS generation oxidative stress is an early step leading to cellular damage after exposure and consequently changes in ERG (retinal function). MF exposure causes apoptosis in retinal tissue.