Post-use symptoms can include: eye strain; eye or muscle twitching; involuntary movements; altered, blurred, or double vision or other visual abnormalities; dizziness; disorientation; impaired balance; impaired hand-eye coordination; panic or anxiety attack; excessive sweating; increased salivation; nausea; lightheadedness; discomfort or pain in the head or eyes; drowsiness; fatigue; or any symptoms similar to motion sickness, as well as excessive drowsiness and decreased ability to multitask. Do not drive, operate machinery, or engage in other visually or physically demanding activities that have potentially serious consequences until you have fully recovered from any symptoms.