Visual acuity, the character of fixation, the angle of deviation, refraction, monocular determination of accommodation and blood supply of the ciliary body have been studied in 50 schoolchildren (100 eyes) with convergent strabismus and amblyopia of various degree. Children with amblyopia of high and moderate degrees have shown a sharp fall or absolute absence of the positive part of relative accommodation and reduced blood supply of the ciliary body. Between the mentioned indices and degree of amblyopia there exists a positive connexion.