What are ways to prevent drooping eyelid?

See eye doctor: First make sure you don't have a medical problem with the connection between the nerve and the muscle which would manifest itself as drooping worse when tired or end of the day. Genetics play a big role. Also, having birthdays plays a big role. Try to reduce sources of inflammation such as allergies and irritants. Avoid smoking and smoke. Avoid uv light.

Find out cause: A new onset of drooping eyelid (usually on one side) should be evaluated by an ophthalmologist (eye md) and/or a neurologist. While some conditions are benign & may be readily repaired by lid surgery, other causes such as certain lesions or a horner's syndrome need greater evaluation.