From
eHow:
A primary ingredient used in over-the-counter eye drops, particualrly to relieve redness associated with eye irritation, is
tetrahydrozoline, a form of imidazoline. According to the National Institute of Health, tetrahydrozoline, when ingested, is poisonous and emergency medical help should be sought immediately. Possible dangers include:
- Breathing Difficulty
- Eye and Skin Irritation
- Heart Complications
- Stomach Upset
- Disorders of the Nervous System