There are many causes of acute red eye. Clinical features may be suggestive of a particular aetiology and enable treatment to be directed accordingly.
A 23-year-old Swedish nurse on a working holiday in Australia presented to her GP with a two-day history of acute red eyes with a gritty ocular irritation, mild photophobia and a watery discharge. She was not systemically unwell.
When asked about potential ocular exposures, she reported having attended a nightclub seven days previously at which the dance floor had been flooded with foam. She had also recently been on a trip to the Great Barrier Reef, where she had used snorkelling equipment loaned by the tour operator.
Apart from a contraceptive implant, the patient had no general or ocular
history of note. She used no other medications and had no known allergies
to medications or environmental agents. She did not wear contact lenses or spectacles.