Conventional stereoscopic clinical evaluation and imaging of the optic disc with fundus photographs is still the most frequently used and sensitive means of diagnosing glaucoma. Comparison of normal subjects with glaucoma patients with early to moderate visual field defects showed that qualitative optic disc evaluation and Heidelberg retinal tomography measurements had the highest sensitivity, specificity and area under the receiver operator characteristic curves. With some training, it is possible to clinically evaluate optic nerve head and retinal nerve fiber layer stereoscopically and detect early glaucomatous damage. The aim of this communication is to describe the morphological changes of the optic nerve in glaucoma and highlight the techniques of clinical evaluation of the optic disc. However, these may not be available to all clinicians and optic disc evaluation is usually performed at the slit lamp. Several studies have shown that abnormalities in the appearance of the optic disc may precede visual field defects. In the year 2000, approximately 67 million people throughout the world had glaucoma. This disease does not have any symptoms and that is why almost 50% patients are unaware that they are suffering from glaucoma.