Guide to Frenzel Goggles Compared with VNG vestibular testing

Difra Video Frenzel Goggles, videonystagmography


A guide to basic Frenzel goggles, video Frenzel goggles and VNG Equipment

Many clients call to discuss VNG technology, only to be astounded at how expensive videonystagmography VNG devices are.  I  usually ask, "Are you really interested in video Frenzel goggles rather than VNG equipment?"  Most often, the answer is yes, or they want to know more about video Frenzel goggles.

This guide explains the differences to make sure you have the best information to make a good buying decision and, more importantly, receive the product you really need.


Frenzel goggles range in capabilities and price. Basic Frenzel goggles simply light and magnify the eye for observation. Video Frenzel goggles also have a camera to easily observe and record eye movements. Video Frenzel goggles offer a huge step up from basic Frenzels, but that advanced technology does have a direct cost effect. VNG testing equipment is most expensive of all the options. It is used as a diagnostic tool that tracks and records eye movements and nystagmus, using an algorithm to produce a diagnosis.

Frenzel goggles are typically used for the evaluation of patients with vestibular disorders and generally are not used as a diagnostic tool. Basic and video Frenzels are used as a balance assessment and vestibular rehabilitation tool, especially in the administration of various Canalith repositioning procedures (the most popular being the Epley Monocular VideoStar Frenzelmaneuver) for the treatment of benign paroxysmal positional vertigo, BPPV. 

Basic Frenzel goggles do not track the eyes, produce tracings of the eye movements, or generate a report of any kind, although the clinician can observe nystagmus as the patient undergoes various procedures including smooth pursuits, random saccades and Dix Hallpike.

Video Frenzel goggles allow the technician to record a video file of eye movements for a reference point during and post-therapy, including Canalith repositioning procedures. Video Frenzels provide far better capabilities for more positive vestibular rehab outcomes.  

VideoStar™ video Frenzels, manufactured by Difra Instrumentation, include another important feature not found on most competitive products.  With VideoStar™ Frenzels, you can record and project the image of the patient's movements onto a wall-mounted monitor or on the laptop in real-time, for improved patient treatment.

VideoStar™ Frenzels also include audio recording so the technician can see and hear the commands and review the session at a later time. As with basic Frenzel goggles, video Frenzel goggles do not produce a report of any kind, only video files of the patient encounter.


--Used as a balance assessment and vestibular rehabilitation tool

--Optical magnifying glasses with lighting

--No camera or ability to record the eye movements

--Cost is around $500

--Not available from Secure Health, Inc.


--Used as a balance assessment and vestibular rehabilitation tool

--Optical magnifying glasses with lighting

--One-camera (monocular) or two-camera (binocular) configurations

--Record a video file of eye movements, but do not produce a report of any kind

--VideoStar™ Frenzel goggles offer exclusive feature with video recording projected onto a monitor or laptop

--Cost is around $4,000, depending on features

--VideoStar™ Frenzel goggles are manufactured by Difra Instrumentation and available from Secure Health, Inc. 



--Used to identify, diagnose and treat vestibular disorders

--One-camera (monocular) or two-camera (binocular) configurations

--Produces automatic reports marking nystagmus

--Cost starts at $20,000, depending on features

--HeadStar™, HeadStar E-Z™ and NysStar™ VNG devices are manufactured by Difra Instrumentation and available from Secure Health, Inc.

VNG technology is the gold standard for vestibular diagnostics.  As with VideoStar Frenzels, VNG devices are available in both one-camera (monocular) or two-camera (binocular) configurations. In addition, many VNG devices offer a wide range of features, including the video recording of the eye/s as the patient undergoes diagnostic tests.

Unlike basic or video Frenzels, VNG technology tracks the eye movements and plots the results on reports where the report is then interpreted by a qualified physician.  VNG technology helps diagnose vestibular or central nervous system CNS issues.

Every VNG system uses complex algorithms to plot eye detection and movements.  Some VNG brands do not automatically identify the nystagmus, but rely on the technician to mark the data by manually reviewing the eye tracings and selecting the extremes examples of nystagmus. Manual marking of test reports is time consuming and subject to human error. We offer VNG products manufactured by Difra Instrumentation, including automatic computerized marking or manual marking of nystagmus. Most everyone uses the automatic feature for its accuracy and time-savings benefits.

Most VNG devices offer smooth pursuits, random saccades, OPK, spontaneous nystagmus, gaze, Dix-Hallpike, body positioning, and positional and caloric irrigation testing.  Other tests that may be offered include the active head rotation test and vHit technology.  The Difra products we offer automatically compile each test into a report once all test sequences are completed.  The reports require a qualified physician who has been trained to interpret the results for an accurate diagnosis.

VNG technology is significantly more expensive than basic or video Frenzels and for good reason.  The eye-tracking software is extremely complex and the costs of hardware are much higher than the technology used for video Frenzel goggles.

We offer three versions of VNG technology manufactured by Difra Instrumentation. Prices start around $20,000 and go up from there, depending on features added.

The right choice: One or Two Camera VNG?

In conclusion, if you are interested in an assessment tool for rehabilitation and treatment of vestibular disorders, consider video Frenzel goggles. If you need vestibular diagnostics and the ability to produce test reports, then VNG technology is your best option.  

The information offered here is a brief comparison and is by no means a complete look at these technologies.  For more information on all of the products or discuss a specific application,  please contact me at [email protected] or by calling 260.804.4041.  I would appreciate hearing from you.

--Dan Scherer, CEO

Secure Health, Inc.

260.804.4041 or [email protected]








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