Naphazoline drops. The adverse reactions include: ocular: mydriasis, increased redness, irritation, discomfort, blurring, punctate keratitis, lacrimation, increased intraocular pressure. Systemic: dizziness, headache, nausea, sweating, nervousness, drowsiness, weakness, hypertension, cardiac irregularities, and hyperglycemia.
Rebound Redness. Naphazoline hydrochloride is used as a eye redness reliever. It temporarily constricts blood vessels to "whiten" the eye. However, with prolonged use for more than a few days, the redness can "rebound" as the drug wears off after a few hours, prompting ever increasing use of the drug (like an addiction). The increased use can lead to irritation or toxic reactions. It can also raise blood pressure.