Inclusion Criteria:  Intraocular pressure below 21mmHg  Exclusion Criteria:  Positive Klein test Use of medications that affect the circulatory system in up to one month before the procedures; Caffeine use 24 hours before procedures; Presence of ophthalmic diseases; History of hypertension or diabetes; Blindness; Tumor in the head; Skull or cervical fractures that occurred less than 6 months ago.