ZEISS IOLMaster 500 Trusting the experience of 100 million IOL power calculations

The IOLMaster® 500 from ZEISS is the gold standard in optical biometry, with more than 100 million successful IOL power calculations to date. The ZEISS IOLMaster 500 is a great choice for cataract surgeons looking for a reliable, fast and easy-to-use optical biometer for measurements they can depend on.

  • Refractive outcomes you can trust
  • Fast and easy to use
  • Advanced measurement of challenging eyes
  • Precise and efficient markerless toric IOL alignment7,8
product video IOLMaster 500

Refractive outcomes you can trust

The ZEISS IOLMaster is the only optical biometer to feature distance-independent telecentric keratometry.

It enables robust and repeatable measurements and shows excellent agreement with manual keratometry while achieving higher precision.1 In combination with a wide variety of established formulas, you can achieve refractive outcomes you can trust.2

ZEISS IOLMaster 500 with telecentric keratometry

ZEISS IOLMaster 500 Fast and easy to use

Fast and easy to use

A well-designed user interface, plausibility checks, distance-independent measurements and a reading that’s up to 4 times faster compared to other optical devices provide outstanding usability and reduced chair time.3 You can measure both eyes in less than 60 seconds4. A difference you, your team and your patients will notice every day.

ZEISS IOLMaster 500 measures challenging eyes

Advanced measurement of challenging eyes

In denser cataracts the ZEISS IOLMaster 500 achieves a measurement success ratio that is up to 20% higher than that of other optical biometers5, allowing a cataract penetration rate of more than 93%6. Even with staphyloma, pseudophakic and silicone-filled eyes, the ZEISS IOLMaster 500 measures along the visual axis. And with its Haigis-L formula, the ZEISS IOLMaster 500 allows IOL calculation for myopic and hyperopic post-LVC cases.

ZEISS IOLMaster 500 - Markerless toric IOL implantation

Precise and efficient markerless toric IOL alignment7, 8

The ZEISS IOLMaster 500 is an integral part of the ZEISS Cataract Suite. A reference image is acquired and used for intraoperative matching with the live eye image during cataract surgery. Manual marking steps can be skipped altogether for efficient8 and more precise7 toric IOL alignment with reduced residual astigmatism.9


    • IOLMaster 500 Brochure EN

      Pages: 8
      File size: 734 KB


ZEISS IOLMaster 500

Measurement range
Axial length 14 – 38 mm
Corneal radii 5 – 10 mm
Anterior chamber depth 1.5 – 6.5 mm
White-to-white 8 – 16 mm
Display scaling
Axial length 0.01 mm
Corneal radii 0.01 mm
Anterior chamber depth 0.01 mm
White-to-white 0.1 mm
IOL calculation formulas

Haigis, Hoffer® Q, Holladay 1 and 2, SRK® II, SRK® / T

Clinical history and contact lens fitting method for calculation of corneal refractive power following refractive corneal surgery
Haigis-L IOL calculation for eyes following myopic / hyperopic LASIK / PRK / LASEK surgery
Calculation of phakic anterior and posterior chamber implants
Optimization of IOL constants
Ultrasound data link

ZEISS eyecare data management system FORUM®

ZEISS computer-assisted cataract surgery system CALLISTO eye (via USB)
Data interface for electronic medical record (EMR) / patient management systems (PMS)
Data export to USB storage media
Export database for Holladay IOL Consultant and HIC.SOAP Pro
Ethernet port for network connection and network printer
Line voltage
100 – 240 V ± 10 % (self sensing)
Line frequency
50 – 60 Hz
Performance consumption
max. 75 VA
Laser class

Optimized lens constants


Download optimized lens constants for more than 300 IOL models based on the data from over 50,000 cataract surgeries.

  • 1

    Bullimore MA, Buehren T, Bissmann W, Agreement between a partial coherence interferometer and 2 manual keratometers, J Cataract Refract Surg   

  • 2

    Aristodemou P, Knox Cartwright NE, Sparrow JM, Johnston RL, Intraocular lens formula constant optimization and partial coherence interferometry biometry: Refractive outcomes in 8108 eyes after cataract surgery, J Cataract Refract Surg. 2011 Jan;37(1):50-62

  • 3

    Chen YA, Hirnschall N, Findl O, Evaluation of 2 new optical biometry devices and comparison with the current gold standard biometer, J Cataract Refract Surg. 2011 Mar;37(3):513-517

  • 4

    Depending on experience of operator and eye conditions   

  • 5

    Rivero L, IOLMaster Version 5 vs. Lenstar LS900, presented at 2010 AAO – MEACO Joint Meeting in Chicago, Illinois   

  • 6

    R. Varsits, N. Hirnschall, B. Doeller, O. Findl; Increasing the number of successful axial eye length measurements using swept-source optical coherence tomography technology compared to conventional optical biometry; presented at ESCSR 2016

  • 7

    Proof for “precise”: Clinical data of Prof. Findl / Dr. Hirnschall presented at ESCRS 2013 – technically verified pre- / intraoperative matching precision ± 1.0° in mean.

  • 8

    Proof for “efficient”: W. Mayer (2017). “Comparison of visual outcomes, alignment accuracy, and surgical time between 2 methods of corneal marking for toric intraocular lens implantation”. JCRS, October 2017

  • 9

    Clinical data of Dr. Black presented at ESCRS 2014 – 99% of patients had a postoperative refractive cylinder within +/- 0.50 D.