Introduction The question of whether and how the act of accommodation influences the level of the intraocular pressure has been investigated and discussed ever since the inception of scientific ophthalmology. In spite of this, the answers have remained equivocal. Yet, unequivocal answers would be helpful in deciding whether it is true, as some authors assume, that close work has a deleterious effect on the eyes of patients with early glaucoma or whether, as others think, close work by such patients should not be discouraged but, if anything, encouraged. The question of the effect of the act of accommodation on the level of the intraocular pressure has become particularly important in recent times with the introduction of tonography for the study of the fluid exchange in the eyes. If accommodation should influence the intraocular pressure in one way or another, this could be a factor which might significantly affect the tonogram