An instrument you can rely on for years to come

Haag-Streit offers a comprehensive range of tonometers and accessories.

Whether you’re seeking the gold standard in tonometry—the Goldmann applanation tonometer—or a convenient hand-held option in the Perkins applanation tonometer, you can count on reliable performance.

Goldmann tonometer AT 900
The Goldmann Tonometer

The gold standard in tonometry

Enjoy the most accurate IP measurement with the Goldmann Applanation Tonometer AT 900®. It is a powerful accessory to the Haag-Streit 900 series slit lamps, allowing IOP measurements to be taken with the patient at the slit lamp as part of a routine exam.

Achieve the best IOP measurements
The Applanation Tonometer remains the most widely used instrument to measure interocular pressure. Its benefits include:

  • A high accuracy of measurement: when using the correct procedure, the average deviation in a single exam does not exceed ± 0.5 mm Hg.
  • Best reproducibility
  • Reliable and durable
  • Can be used with virtually any slit lamp

Enhance the accuracy of your measurements.

The Goldmann Tonometer

Considerations in using the Goldmann tonometer

  • The intraocular pressure in mm Hg is found by multiplying the drum reading by ten.
  • Reusable tonometer prisms avoid the need for time-consuming and laborious cleaning and disinfection.
Goldmann tonometer with reusable prism
Hand held Perkins applanation tonometer
The Perkins Tonometer

Treat patients cost-effectively & conveniently

The hand-held Perkins applanation tonometer has been a world standard for over 30 years. Based on Goldmann principles for assessing intra-ocular pressure, the Perkins tonometer combines proven clinical accuracy with the flexibility of a hand-held instrument.

This tonometer is compatible with both Haag-Streit Tonosafe disposable prisms and reusable Goldmann tonometer prisms.

The Perkins Tonometer

Versatility for treating a range of patients

Convenience and versatility was a primary concern in the design of this instrument. The Perkins tonometer was designed to treat patients who are difficult to examine, such as post-operative, bed-ridden, and pediatric patients. It’s also a more cost effective option for busy clinics and practices with limited resources.

get a quote
View of the human eye
Perkins tonometer offers proven accuracy and visibility
The Perkins Tonometer

Proven accuracy and visibility

The Perkins offers proven accuracy and brilliant visibility. Precision counter-balanced movements allow you to take readings with the patient in any position. The illumination system provides superior fluorescein, greatly enhancing the "semi-circles" that are vital to attaining accurate results and permitting use regardless of ambient lighting conditions.

Every Perkins Tonometer is calibrated to the highest quality standards and comes with a Certificate of Accuracy.

The Perkins Tonometer

The Perkins Examination Telescope

The optional Perkins Examination Telescope (P.E.T.) allows magnified viewing of the fluorescein "semi-circles" at arms length, making examinations more comfortable for both the ophthalmic professional and the patient. And because the P.E.T. enables two people to view simultaneously, it can be used as an effective teaching aid.

Experience the portability and accuracy.

Perkins examination telescope
Carrying case for the Perkins tonometer
The Perkins Tonometer


The Perkins Tonometer comes standard with a lightweight, compact carrying case, Goldmann Prism and battery operated handle taking four AA size batteries. Accessories include a rechargeable handle and recharging unit.


Which tonometer with which slit lamp

Depending of the slit lamp, the Haag-Streit Goldmann applanation tonometers have different ways of how they are mounted.

AT 900 tonometer
Fixation for type BQ/BP

Type BQ / BP

The Applanation Tonometer type BQ / BP fits the Haag-Streit slit lamps BQ 900 and BP 900. It provides a parking position and can be easily placed into working position. The applanated surface is observed monocularly through the right eyepiece of the stereo microscope.

Tonometer fixation

Type R

The applanation tonometer type R fits the BI 900, BM 900 and BD 900 as well as many 3rd party slit lamps.It can be left on the slit lamp permanently. It is fastened to the microscope on a mounting base and swivelled in front of the microscope for the examination. The observation of the applanated surface is conducted monocularly – only through the left eyepiece.

Fixation type R
Fixation type T
Tonometer fixation

Type T

The Applanation Tonometer type T fits the Haag-Streit slit lamps BQ 900, BP 900, BM 900 and BI 900. It is set on a guide plate over the slit lamp axis. The instrument can be moved between two positions on the guide plate for observation through the right or left eyepiece. The tonometer is placed on the slit lamp only when applanation tonometry is performed.

Comparison Chart

Find the right tonometer for your slit lamp

SLIT LAMPTonometer Model AT 900®
*Haag-StreitAT 900® Mod. RAT 900® Mod. TAT 900® Mod. BQ
Slit Lamp BD 900® LED
Slit Lamp BM 900® LED
Slit Lamp BI 900®
Slit Lamp BP 900® LED
Slit Lamp BQ 900® LED
Slit Lamp BX 900® LED