Possibility of permanent change in eye colour. Patients w/ herpetic keratitis. Macular oedema in aphakic patients, in pseudophakic patients w/ torn posterior lens chamber lenses or in patients w/ known risk factors for cystoid macular oedema; predisposing factors for iritis/uveitis. Asthmatic patients. Periorbital skin discoloration. Benzalkonium Cl content may cause punctuate keratopathy &/or toxic ulcerative keratopathy. May affect ability to drive or operate machinery. Pregnancy & lactation. Childn <1 yr.