Memorial Eye

                            Doctors of Optometry

Experts in EyeCare    

During a comprehensive exam, various tests are performed to ensure that if any eye disorder is present, it is detected at the earliest possible stage.

Intraocular pressure (IOP) is measured with a Non-Contact Tonometer (NCT). It gently blows a puff of air toward the eye. It collects the air that "bounces off" the eye to determine the pressure inside. IOP is an important indicator of the overall "state of the eye", and is often referred to as "the glaucoma test". IOP is not the only factor in making a diagnosis of glaucoma, and IOP can be influenced by many ocular disorders, including injury, inflammation, and medications.

This is measured with an instrument called an autorefractor. This approximates your glasses prescription. The autorefractor also takes a keratometry measurement, which is the curvature of the front surface of the cornea. Keratometry is used to aid in the fitting of contact lenses, as well as detecting irregularities in the corneal surface.

Our visual field screener utilizes a state-of-the-art technology called "Frequency Doubling Technology" to screen the sensitivity of the retinal nerve endings that make up the optic nerve. While the patient views a central target, shimmering bars of light are presented in the peripheral field of vision. The patient responds as the images, which vary from very bright to very dim, are detected. The FDT technology provides an excellent way to screen not only for glaucoma, but also other retinal and neurological disorders as well.

Visual acuity is a measurement of the smallest detail an eye is able to detect. This is measured with and without corrective lenses, at far and near distances. Standard testing distances are 20 feet (for far vision), and 16 inches (for near vision). Prescriptions for lenses are adjusted for an individual person's preferred working distances. The standard for "perfect" vision is described as "20/20". If the distance acuity of an eye is measured to be "20/40", it means, basically, that the eye is able to detect at 20 feet what the "perfect" eye can detect at 40 feet.

Color vision deficiencies, particularly among males, are quite common. Most deficiencies result from an inherited condition which remains stable throughout life. Changes in color vision are NOT normal. Certain diseases, trauma, or medications can cause color vision to change. Color vision screening is relatively simple, and involves identifying numbers within colored patterns.

Because eyes are affected by the general condition of the rest of the body, blood pressure is measured during every comprehensive exam.

SUBJECTIVE REFRACTION

During this portion of the eye exam, the doctor and patient work together to "fine tune" the final spectacle prescription. Projected images are viewed through a series of prescription lenses, which are housed in an instrument called a "phoropter". The patient selects the views that provide the sharpest vision, until a finalized prescription is determined. With a finalized prescription, customized glasses can be produced, and contact lens parameters determined.

During this portion of the exam, the doctor may use one or several techniques to assess the ability of the two eyes to work as a team. The flexibility and accuracy of the focusing system, as well as the ability of the eyes to maintain a constant, single image at long and short distances are evaluated. If a deficiency is detected, it may be incorporated into the glasses prescription.

Ocular instruments with very high magnification are used to microscopically evaluate all external and internal structures. Evidence of diabetes, high blood pressure, and high cholesterol are often seen in the eye before a patient is aware that there is a problem. Cataract, glaucoma, and macular degeneration are just a few of the problems that are detected during this portion of the exam. For a truly complete evaluation, pupil dilation is recommended.