Coats' disease is a disease of small vessels in the retina that can, in the absence of treatment and adequate care, lead to total loss of vision in the affected eye. It mainly affects very young male children without any history or particular context. In babies, it is difficult to diagnose and treatment is often given too late. The disease leads to the development of lesions in the retinal blood vessels responsible for sub- and intra-retinal exudations that, in turn, lead to retinal lesions and consequences for eyesight. The treatment based on the destruction of the vascular abnormalities by laser photocoagulation is effective. Regular ophthalmological monitoring is then required to diagnose and treat the relapses frequently observed in this disease.