A 10-year-old boy complains of pain in his left eye and strong photophobia after he has injured his left eye with a pencil at school. Left eye examination revealed: blepharospasm, ciliary and conjunctival congestion, cornea is transparent, other parts of eyeball have no changes. Visus 0,9. Right eye is healthy, Visus 1,0. What additional method would you choose first of all?