κατάκλᾰσις · kataklasis — LSJ
forced position, τῶν ἄρθρων Hp. Epid. 6.1.15 (pl.).
κ. ὄμματος drooping of the eyelid, Id. Prorrh. 1.84 (vv. ll. -κλισις, -κλεισις), cf. Epid. 6.1.15, Gal. 16.675.
refraction of light or sound, opp. ἀνάκλασις (reflexion), Arist. Pr. 901b20, 904b30, Cleom. 2.6.