In short: either works. Closed eyes help you turn inward; half-open eyes, resting softly on the floor in front of you, help if you get sleepy. Choose one and keep it for the session.
Questions people ask
Should I close my eyes when meditating?
Either is fine. Close them to turn inward; keep them half open, gazing softly down, if you tend to get sleepy. If drowsiness persists, the Buddha suggested washing the eyes and looking at the sky (AN 7.61).