Your patient has a corneal ulcer

Is the eye red? If not, there is unlikely to be an infective corneal ulcer.

Stain the eye with fluorescein. If it stains, there is an ulcer. If the eye is white and the cornea does not stain, the white opacity in the cornea is likely to be related to an old scar.

If the patient does have a corneal ulcer they should be referred urgently.