This study aimed to demonstrate metaplastic changes in a wide area of conjunctival epithelium using the mapping technique by colouring different stages of metaplastic changes after marking them on a millimetric scale paper under a light microscope. Data of 23 patients were studied: 19 contact lens wearers, 2 cases with dry eyes, 1 with lagophthalmus, 1 with conjunctivitis, and 13 normal subjects as controls. Cellulose acetate paper cut into crescents was applied to nasal and temporal quadrants of the conjunctiva. After evaluating the collected cells under light microscopy, they were marked on a millimetric scale. Almost all the patients had varying degrees of squamous metaplasia; however, significant differences were observed in the distribution and the percentage ratio of these changes. In conclusion the colour-coded mapping method yields valuable information in a broader perspective for determining the distribution and degree of the ocular surface changes caused by different physiological and pathological circumstances. Copyright (C) 2002 S. Karger AG, Basel.