Acute trachoma | TF | Trachomatous inflammation—follicular | Presence of five or more follicles at least 0.5 mm in diameter, in the upper tarsal conjunctiva |
| TI | Trachomatous inflammation—intense | The tarsal conjunctiva appears red, rough and thickened. There are usually numerous follicles which may be partially or totally covered by the thickened conjunctiva |
Cicatricial trachoma | TS | Trachomatous scarring | The presence of scarring in the tarsal conjunctiva. Scars are easily visible as white lines, bands, or sheets in the tarsal conjunctiva |
| TT | Trachomatous trichiasis | At least one eyelash rubs on the eyeball. Evidence of recent removal of inturned eyelashes should also be graded as trichiasis |
| CO | Corneal opacity | The pupil margin is blurred viewed through the opacity. Such corneal opacities cause significant visual impairment (less than 6/18 or 0.3 vision), and therefore visual acuity should be measured if possible. |