Pre-exam testing: during pre-exam, our certified technicians perform a thorough assessment of your eyes with a variety of tests to assist the doctors in better determining the health of your eyes. A baseline prescription for eyeglasses and/or contact lenses is also determined.

The following tests are administered:


An instrument called a non-contact tonometer is used to check the intraocular pressure inside the eye. A puff of air is directed toward the cornea of the eye to determine the pressure. This test is used to detect glaucoma. Glaucoma is the sneak thief of sight as there are few symptoms until the final stages of the disease. Early detection is extremely important in providing a treatment regimen.

Blood Pressures

You are no doubt aware that high blood pressure is a serious problem. Undetected or untreated, it can lead to stroke, heart disease and kidney disease. It can also cause blindness. For this reason, as part of your thorough eye examination, we routinely check your blood pressure during pre-examination testing. The doctor will also check for blood pressure that may be out of control during your eye examination when he or she examines the blood vessels inside your eyes.

Color Vision Testing

A color vision test checks your ability to distinguish between different colors. The test is done to determine if you have any problems in your color vision or to determine how well your optic nerve works. The optic nerve is the main nerve connecting the eye to the brain. Changes in color vision can often be the first sign of a vision problem.


This test assists us in determining a baseline prescription for eyeglasses/contact lenses. It also shows the shape of your cornea to assist with the fitting of contact lenses.


The autoperimeter is used to determine the limits of your central and peripheral (side) vision. It can also detect early visual field loss.

Assessment of Current Eyewear/Contact Lenses

We measure the prescription in your current eyewear to help us assess any visual problems you may be experiencing and to assist us in determining a suitable prescription for your new prescription.


The Optomap Retinal Exam assesses the health of your retina and provides a safeguard for you and your family against health threats and can help prevent possible loss of vision. This optional testing procedure gives Drs. Littlefield, Broderick & Hamilton the most complete view of the back of your eyes available today, enabling early problem detection, without the discomforts typically associated with pupil dilation such as blurred vision and sensitivity to light.

Visual Acuities

The visual acuity test is used to determine the smallest letters a person can read on a standardized chart or card held 14-20 feet away. Visual acuity is expressed as a fraction. The top number refers to the distance you stand from the chart. This is usually 20 feet. The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read. For example, 20/20 is considered normal. 20/40 indicates that the line you correctly read at 20 feet can be read by a person with normal vision from 40 feet away.


Your eyes may be dilated with drops that cause your pupils to enlarge. With your pupils dilated, the doctors can better examine the inside of your eyes and tell if your eyes are healthy. Dilation is very safe and it is unlikely that you will experience much inconvenience or discomfort. Dilation, when needed, provides you with the most thorough eye health examination possible. You and your eyes will be healthier for it. It is always recommended that you come to your visit accompanied by a driver as your near vision may be compromised for several hours.

Special Testing


The HRT/OCT represents the most current advancement in the management of glaucoma. Its technology allows the doctors to image your optic nerve and the surrounding nerve fibers of the retina. Repeated over time, these optic nerve images are precisely measured. Fine changes to the tissue of the nerve are detected by the instrument.

Peripheral Vision Loss.

This is specialty testing for glaucoma patients or other individuals who are experiencing changes in their vision. It helps determine the progression of the disease and assists the doctors in providing treatment. For other individuals, it can help to isolate if there is a problem with the visual system anywhere along the visual pathway: from cornea to occipital lobe in the brain.

Corneal Topography

The cornea is mapped to determine it’s shape and steepness to assist the doctor in determining whether or not a patient is eligible for laser vision correction. It is also useful for tracking and assessing corneal dystrophies such as keratoconus or pellucid marginal degeneration.


This specialized testing is performed to determine intraocular pressure when tracking specific diseases of the eye.


The pachymeter ultrasonically determines the thickness of the cornea and is used to help determine whether or not a medical condition is present.


Visual Evoked Potentials (VEP) is a specialty test to determine if there is damage to the visual pathway. It is a novel instrument for the monitoring of amblyopia and can help to show children and parents that there is progress being made (or in some unfortunate cases that no progress has been made) with regards to the treatment protocols that your optometrist has prescribed. The VEP can also be used to assess and monitor a number of other disease processes that can affect the visual pathway: glaucoma, optic neuropathies, visual disturbances, multiple sclerosis, among many others!

Results from Pre-Examination Testing procedures are given to the doctor before he or she performs your eye examination.

During the eye examination, the doctor will look for the following:

  • Your ability to see clearly at near and at far distances
  • Your ability to change focus efficiently and comfortably
  • Your ability to use both eyes as a team
  • Vision conditions like nearsightedness, farsightedness, astigmatism and presbyopia
  • Eye diseases like glaucoma and conditions like cataracts
  • General health conditions like diabetes and high blood pressure that can often be detected in the eyes
  • All the results from the pre-examination testing are coordinated with the results from the doctors’ examination of your eyes and your family medical history. All of this information is used to determine the health of your eyes and a prescription based on a high level of professional skill and judgment.

More than 40 million low-income, working people in the United States cannot afford the cost of routine eye care or the health insurance that covers it. VISION USA (1991) is a program developed by doctors of optometry to help these people by providing basic eye health and vision care services free of charge.

MAINE OPTOMETRY, P.A. is proud to participate in this worthwhile program. Anyone wishing to learn more about the program and eligibility requirements should visit the VISION USA web site at: or telephone 1-(800) 766-4466, 7:00 a.m. to 9:00 p.m., CST, Monday through Friday.

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