Black eyes before squatting

This situation is common with orthostatic hypotension: Orthostatic hypotension is due to changes in posture, such as a sudden transition from a supine position to an upright position, or hypotension that occurs when standing for a long time. Orthostatic hypotension is generally considered to be a decrease in systolic blood pressure of 20 mm Hg or a diastolic blood pressure of 10 mm Hg after standing compared to the supine position.