Low-power lasers are used for some time in the treatment of numerous diseases, although the physical mechanism of the effects of their actions is very unclear. To examine the relationship between the parameters of the laser light and its biological effects, we conduct a systematic study involving laser irradiation of biological samples with low power. Preliminary measurements of morphological parameters of blood are very promising because we detected their close correlation with exposure. Our next goal is to optimize this effect and create a biophysical model.