A randomized, double masked, study was designed in order to investigate the relationship between the central thickness of hydrogel contact lenses and the overall comfort of patients with tear deficiency. To allow for statistical analysis, a thin lens was fitted in one eye and a thicker lens of the same characteristics in the contralateral eye. Subjects were asked to wear the lenses for 30 days on a normal daily wear basis and to graduate several factors such as comfort, dryness sensation, redness, photophobia, tearing, quality of vision and others. The results indicate that thicker lenses were preferred in terms of comfort, dryness sensation, photophobia and handling whereas thinner lenses were considered to give a better quality of vision. As a whole, thicker lenses were better tolerated by the patient. Central thickness was found to be of significant relevance when choosing a contact lens, especially when the tear film is deficient.