During a regular eye examination, an ophthalmologist checks the intraocular pressure (IOP), i.e., performs tonometry. The indicators during eye tonometry depend on when and how the IOP is checked. In the morning, data can be higher by 2-3 units. This is related to the horizontal position of the body during sleep, slowed breathing and pulse, and the predominantly parasympathetic nervous system’s activity. By evening, the intraocular pressure usually decreases. Also, results can vary depending on the technique chosen by the doctor.

The frequency of measuring intraocular pressure depends on the health status of the eyes and the doctor’s recommendations. People with an increased risk of developing glaucoma are usually advised to measure the pressure several times a year. For people without vision problems, this can be part of an annual medical examination. If you have already been diagnosed with vision problems or are at risk, it is better to follow the doctor’s recommendations regarding the frequency of measurements.

The normal eye pressure in adults using contact measurement techniques is considered to be 10-21 mmHg. Modern devices allow measurements using an electronic-optical system without contact with the cornea. For non-contact tonometry of the eye, the norm is 12-21 mmHg.

Children’s IOP indicators differ from adults. In a child, it increases with age by approximately 1 mmHg every two years. In childhood, the indicator equals 12-14 mmHg, at 12 years old - 18±3 mmHg with contact measurement technique.

Mandatory indications for measuring ophthalmotonus are:

• retinal detachment;
• glaucoma;
• diabetes and other endocrine diseases;
• post-surgical complications of the visual organs;
• neurological pathologies;
• hypertensive disease;
• age over 40 years.

For preventive purposes, adults aged 19-39 are recommended to measure intraocular pressure once every 3 years. Upon reaching 40 years - annually or once every 6 months. In cases of glaucoma and other eye diseases, the frequency of IOP determination is established by an ophthalmologist.

In most people with ocular hypertension at the initial stage, no symptoms are detected. For this reason, an examination by an ophthalmologist is very important to exclude damage to the optic nerve and vision loss due to high pressure.