Testing Instrumentation

Our Testing Instruments

We utilize many instruments and specialized equipment to help evaluate your eye health and treat your eye conditions. Some of these instruments are used for routine eye exams, and others are for analysis of specific eye health conditions. This page will give you an idea of what to expect from some instruments and the reasoning behind their use.


Auto-Refractor Keratometer

Auto-Refractor Keratometer

This instrument automatically measures an objective refraction, or theoretical refraction of what lens powers you should need to see good in the distance.  You just look into the instrument where you see a picture. The instrument looks to see where light focuses on the back of your eye, and what lenses it would take to make the image focus in the right area.  It measures sphere, cylinder and axis for each eye, as well as radius of curvatures and axis for the cornea of each eye. These measurements will give us a good idea if you have a change in your prescription, or a starting point to determine the ideal prescription for you.  The auto-refractor can be an invaluable tool for children and other patients whose responses are not reliable.

Slit Lamp

Slit Lamp

The slit lamp is a combination of a horizontal microscope combined with a high intensity light.  We use the slit lamp to look at the different parts of your eyes. By varying the power of the microscope and the color and intensity of the lighting, the doctor will inspect your eyes from front to back.

Non-Contact Tonometry

Visual Field Analyzer

The Zeiss Humphrey Visual Field Analyzer is also known as a peripheral or side vision test.  We use this instrument for glaucoma patients and suspects, patients having headaches, visual disturbances, decreased vision, blind spots, and some systemic conditions.  When taking this test, you will watch a fixation light in the back of the instrument. The instrument will then flash other lights around the center light. When you see another light flashed, you will push a button to let the analyzer know you see the light.  The instrument is calibrated for your age and will vary the intensity of the lights to enable us to evaluate any changes to the sensitivity of different parts of your retina.


We utilize 3 different methods of measure intraocular pressure in our office

Goldmann Tonometry

Non-contact tonometry

The only type of instrument that can measure pressure in your eye without touching it.  This method of is done with a light puff of air. The Reichert Non-Contact Tonometer (NCT) measures the response of your eye to the puff.  You lean against the top with your forehead and look at the lights. The lights will align with your eye, come up close, and blow a light puff of air at your eye. 

Icare Tonometry

Goldmann tonometry

The original method of intraocular pressure measurement and standard for decades.  After an eye drop is put in to tint the tears and numb your eye surface, the doctor will touch the tonometer tip to your eye and measure the resistance of deflection of your eye.

Icare tonometry

The Icare tonometer does not need and eye drops to measure.  It is just a gentle touch to the eye surface that feels only like a tickle.