Glaucoma is a multifactorial disease, an important risk factor of which is increased intraocular pressure. Fluctuations in intraocular pressure are often associated with vaginal birth, although intraocular pressure during active pushing during stage II has never been measured.. The study will be conducted on a group of patients with healthy eyes on patients who have completely fine vision or have a small refractive error and are accustomed to wearing contact lenses. The measurement of intraocular pressure itself will be carried out using SENSIMED Triggerfish contact lenses, which measure pressure every 5 minutes for 30s. This period roughly corresponds to the duration of 1-2 contractions. Inclusion in the study will be offered to patients in the 35th to 37th week of pregnancy. Prior to measurement patients will be sent to an eye clinic for a detailed examination of both eyes, which includes measuring intraocular pressure. Subsequently, pregnancy checks will take place according to the standard scheme and in the standard scope. At the onset of uterine contractions, an ophthalmologic consultant will be called, which will measure intraocular pressure between contractions using the Tonopen device and put on SENSIMED Trigerfish contact lenses in combination with a local anesthetic. The patient will have these lenses until the end of the third stage of labor, i.e. 2 hours after the birth, when the lenses are removed. In the second stage of labor, continuous monitoring by a cardiotocograph will take place. Subsequently, the obtained data from the cardiotocograph and contact lenses will be evaluated and compared by a team of ophthalmologists and gynecologists, where the investigators will be able to assess the individual fluctuations in intraocular pressure depending on the individual contractions. The aim of the study is to demonstrate or disprove the risks to the glaucoma patient due to increased intraocular pressure during active pushing in combination with uterine contraction.