The purpose of this study was to evaluate the clinical features of keratoconic patients at the National Institute of Ophthalmology. This was a prospective observational study, where 43 patients (65 eyes) with keratoconus were examined and followed from January 2013 to September 2013. There are 33 males and 10 females. Six eyes were in the mild disease stage, 15 eyes were in the moderate stage and 44 eyes in the severe stage. 49.2 percent of patients have a visual acuity (VA) lower than 20/200. Most prominent symptoms are rapid decrease in VA , glare and eye iritation. The signs include Munson sign, Corneal stroma thinning, Vogt striae, Fleischer ring and "scissors" reflex in ophthalmoscope. Keratoconic patients in this study have characteristic clinical features and almost of the patients were in severe stage. "Scissors" reflex in ophthalmoscope is a simple and effective sign for diagnosing keratoconus in the early stage.