/ Products / General diagnostics
Gold standard for over 65 years

Tonometers

Since its introduction in 1957, Haag-Streit's Goldmann applanation tonometry has been the gold standard in intraocular pressure measurement across ophthalmology and optometry. Our tonometer range includes AT 900, an optimally designed solution for every slit lamp, delivering fast, reproducible measurements. For greater flexibility, the Perkins Mk3 hand-held applanation tonometer enables reliable IOP measurement in both clinical and community settings. Both tonometers are compatible with Tonosafe disposable tonometer prisms, which help minimise the risk of cross-infection between patients while delivering  measurement accuracy.

Applanation Tonometer 900

Tonometry Accurate & reproducible IOP measurements

Tonosafe

Tonometry Reduce the risk of cross infection

Perkins MK3

Tonometry Consistent measurement results

Compare our tonometry products

AT 900 model BQ AT 900 model R AT 900 model T
Measuring principle
Goldmann principle ● ● ●
Measuring force generated
Through leverage weight ● ● ●
Via spring weight − − −
Measurement range
Measurement range 0 – 80 mmHg 0 – 80 mmHg 0 – 80 mmHg
Meridian setting
Meridian setting ● ● ●
Measurement deviation
The measurement deviation in the measuring prism is in the measuring range from 0 – 58.84 mN and amounts to a maximum of ±1.5% and to a minimum of ±0.49 mN of the nominal value. ● ● ●
Working settings
Weight (kg) 0.78 kg / 1.72 lbs 0.73 kg / 1.6 lbs 0.49 kg / 1.08 lbs
Width ≤0.49 mN ≤0.49 mN ≤0.49 mN
Working temperature 10° to 40° C / 50°F to 104°F 10° to 40° C / 50°F to 104°F 10° to 40° C / 50°F to 104°F
Tonometer fixation
BQ 900 ● − ●
BP 900 ● − ●
BI 900 − ● ●
BM 900 − ● ●
BX 900 ● − −
Third party slit lamps contact your local distributor contact your local distributor contact your local distributor
Tonometer prisms
Goldmann tonometer prisms ● ● ●
Tonosafe ○ ○ ○
● standard | ○ optional | − not available | □ not recommended

Applanation Tonometer 900

The gold standard in IOP measurement

Clinically proven and trusted by ophthalmology and optometry professionals for more than 65 years, the Goldmann Applanation Tonometer 900 (AT 900) remains the gold standard for measuring intraocular pressure in glaucoma diagnosis. Used with Goldmann measuring tonometer prisms, it delivers reliable optical and mechanical performance for fast, accurate measurements in everyday clinical practice. Available in a range of models, the AT 900 is compatible with both sustainable reusable prisms and convenient single-use Tonosafe prisms.

Read more cta-icon

Tonosafe disposable tonometer prisms

Convenient. Safe. Accurate.

Tonosafe avoids the need for time-consuming cleaning and disinfection without compromising the original Goldmann quality. Developed for single use, it reliably eliminates the risk of cross-infection in all ophthalmic and optometry clinical settings. Calibrated to Goldmann standards, Tonosafe delivers accurate IOP results with both Goldmann and Perkins contact tonometers during glaucoma testing.

Read more cta-icon

Perkins MK3

Ergonomically designed for comfort and balance, the Perkins MK3 hand-held tonometer enables accurate IOP measurements when assessing patients for glaucoma outside the traditional consulting room environment. The Perkins MK3 is compatible with both reusable Goldmann prisms and Tonosafe disposable prisms - widely recognised as the ideal solution for reducing the risk of cross-infection while maintaining the accuracy expected from Goldmann applanation tonometry.

Read more cta-icon