OBJECTIVE To assess the usefulness of the aplanation tonometer (Glaucotest model) for primary care screening of ocular hypertension (OH) in 40 to 80-year olds. METHODS A descriptive prospective study. METHODS Teruel Health Centre (urban). METHODS Users between 40 and 80 of both sexes, selected after four on-demand consultations. The sample was randomised and stratified for age against the general public seeking care. Patients diagnosed with glaucoma or OH, or who were blind for any reason, were excluded. METHODS Measurement of intraocular pressure (IOP) with a Heine Glaucotest aplanation tonometer with a head for 18 mmHg. Those patients with IOP figures above 18 mmHg were referred to the ophthalmology service, so that they could be tested there with a Goldmann tonometer. OH was defined as IOP above 21 mmHg. RESULTS There was a sample of 354 patients, 38% men and 62% women, average age 63.5. A tonometer reading > 18 mmHg was recorded in 49 cases. These were referred to the ophthalmologist, who confirmed IOP in 10 cases (2.8% of the total). The positive predictive value for IOP, with a cut-off point at 18 mm Hg in our study, was 20.4%. 60% of patients with IOP presented risk factors. CONCLUSIONS We found that the aplanation tonometer used was suitable for IOP screening in primary care centers.