<prompt> Which of the following organism can penetrate normal intact cornea?StaphylococcusStreptococcusGonococcusPneumococcus  <response>: Ans. c Gonococcus. Ref: Parsons Disease of eye, 18th ed., 148; Ophthalmology by AK Khurana 2nd ed. 116Three pathogens can invade the intact corneal epithelium and produce ulceration: Neisseria gonorrhoea, CorynebUcterium diptheriae Neisseria meningitidesEducational points:DiseasecauseTime of appearance1Toxic irritation due to Crede prophylaxis 1 silver nitrateA few hours after application of drops2Gonoblennorheaintrapartum infection with Neisseria gonorrhoeae1-4 days postpartum3Other intrapartum infection with bacteria e.g., Streptococcus pneumoniae, Haemophilus influenzae, staphylococci, Pseudomonas aeruginosa, etc.5-7 days postpartum4Intrapartum infection with herpes simplex virus HSV4-6 days postpartum5Intrapartum infection with Chlamydia trachomatis4-15 usually 7 - 10 days postpartum 