<prompt> Organism causing ulcus serpens is:Neisseria gonorrhoeaeCorynebacterium diphtheriaPneumococcusPseudomonas pyocyaneus  <response>: Ulcer serpens is caused by pneumococcus. Ulcer Serpens Greyish white ulcer Organism: Pneumococcus Usually associated with iridocyclitis Stas from periphery and then moves towards centre Has a tendency for perforation May be aw hypopyon 