The TONO-PEN XL applanation tonometer is an easy to use, hand-held instrument that provides IOP readings that correlate closely with Goldmann Tonometry. TONO-PEN’s lightweight ergonomic design and advanced electronic measurement technology enable operators to take fast and accurate IOP measurement with minimal training. Weighing only 2.25 ounces, TONO-PEN XL is extremely portable making it easier to take IOP measurements anywhere on any patient.

Advanced Technology for Accuracy and Repeatability

The TONO-PEN XL tonometer utilizes micro strain gage technology and a 1.0 mm transducer tip. Leading Edge™ recognition software ensures that measurements are taken only at applanation, while ScanLock™ tracking rapidly scans the electronic measurement data at a rate of 500 samples per second. This advanced microprocessor technology produces objective IOP measurements that are less influenced by operator bias than Goldmann tonometry. The average of four independent readings, combined with a statistical confidence index, ensure accurate, repeatable, and reliable tonometry results.

Easy to Use

The TONO-PEN XL tonometer functions in any orientation, making it ideal to use on all of your patients including those in beds or wheelchairs. The device activates with the push of a button and results are displayed clearly on the easy-to-read LCD screen. Patients will appreciate the quick and gentle measurement process.

Clinically Trusted

Clinicians worldwide have made the TONO-PEN XL tonometer a trusted part of their practice for nearly two decades. The proven reliability of the device allows operators to take IOP measurements confidently anytime, anywhere, and in any position.


  • The Tonopen is also an applanation device with a very small “footprint” on the cornea, which makes it easier to use with corneal abnormalities. Since the patient can be done lying or sitting, it is also useful when the patient cannot sit positioned properly at the slit lamp.
  • To use the Tonopen, a sterile cover must be over the tip.
  • The Tonopen must be calibrated by pressing the activation button until “CAL” appears in the window. Hold the Tonopen with the tip straight down toward the floor. When the instrument beeps and “UP” appears in the window, rotate the instrument so the tip is straight up. If “GOOD” appears, press the button again until a double line ==== appears.
  • Ensure that the patient has anaesthetic, and gently tap the Tonopen against the cornea. It should beep with every contact and show the pressure reading. When enough readings have been obtained (usually 4 – 6) it will beep again and display the final averaged reading, with an indicator against the 5%, 10% 20% or >20% level, indicating the confidence of the reading.

Resource from Reichert