At our hospital we use a wide variety of tests & procedures to examine your eyes. The comprehensive eye examination provides the means to evaluate the function health of the eyes & visual system. It also provides the means to identify the presence of other ocular or systematic conditions that may exist without symptoms. Examination is a dynamic & interactive process. It involves collecting subjective data directly from the patient & obtaining objective data by observation, examination & testing. The nature of the eye examination is such that many conditions can produce the same or similar symptoms. For example blurred vision can be result from many causes including uncorrected refractive errors, systematic conditions such as diabetes mellitus or hypertension. In addition potentially blinding conditions such as glaucoma or diabetic retinopathy may cause no symptoms until they are far advanced & the ocular damage is irreparable.
The goals of the comprehensive eye & vision examination are-
a) To evaluate the functional status of the eyes & visual system taking into account special vision demands & needs.
b) Assess ocular health & related systematic health conditions.
c) Establish a diagnosis.
d) Formulate a treatment & management plan.
e) Counsel & educate the patient regarding his or her visual, ocular & related systematic health care status including recommendations for treatment, management & further care.
Some eye & vision tests that you are likely to encounter during eye exam-
Auto Refraction (AR)- We use AR to automatically estimate your eye glass prescription. A chinrest stabilizes your head while you look into the instrument at a pin point of light or a detailed image. It determines the power of your eye required to accurately focus light on your retina.
Non Contact Tonometer (NCT)- NCT is a test that helps detect glaucoma. By directing a quick puff of air onto the eye it can detect elevated eye pressure. The test begins with you putting your chin on the machine’s chin rest. While you look at a light inside the machine, a puff of air will be blown at your open eye. It is completely painless and the tonometer does not touch your eye. Based on your eye’s resistance to the puff of air, the machine calculates your intraocular pressure (IOP). If you have high eye pressure, you may be at risk for or have glaucoma.
Visual Acuity Tests- In this test our optometrists measure the sharpness of your vision. These usually are performed using a projected eye chart to measure your distance visual acuity and a small, hand-held acuity chart to measure your near vision.
Dilated Eye Exam- Dilation is an important part of a comprehensive eye exam because it enables your eye care professional to view the inside of the eye. Drops placed in each eye widen the pupil, which is the opening in the center of the iris (the colored part of the eye). Dilating the pupil allows more light to enter the eye the same way opening a door allows light into a dark room. Once dilated, each eye is examined using a special magnifying lens that provides a clear view of important tissues at the back of the eye, including the retina, the macula, and the optic nerve.
Retinoscopy- In retinoscopy, the room lights will be dimmed and your eye doctor will shine a light at your eye and flip lenses in a machine in front of your eyes. This test estimates which lens powers will best correct your distance vision. Based on the way the light reflects from your eye, your doctor is able to “ballpark” your prescription. This test is especially useful for children and patients who are unable to accurately answer the doctor’s questions.
Slit Lamp Exam- A slit lamp is a binocular microscope (or “biomicroscope”) that your eye doctor uses to examine the structures of your eye under high magnification. It looks somewhat like a large, upright version of a microscope used in a science lab. During the slit lamp exam, you will be asked to place your forehead and chin securely against the rests on the front of the instrument and your doctor will begin by examining the structures of the front of your eyes — including your eyelids, cornea, conjunctiva, iris, and lens. With the help of a hand-held lens, your doctor may also use the slit lamp to examine structures located farther back in the eye, such as the retina and optic nerve.
A wide range of eye conditions and diseases can be detected with the slit lamp exam, including cataracts, macular degeneration, corneal ulcers and diabetic retinopathy, etc.
Glaucoma Test- Apart from NCT another type of glaucoma test is performed with an instrument called an Applanation Tonometer. For this test, your eye doctor will put yellow eye drops in your eye to numb it. Your eyes will feel slightly heavy when the drops start working. This is not a dilating drop, it is a numbing agent combined with a yellow dye that glows under a blue light. Then the doctor will have you stare straight ahead into the slit lamp while he or she gently touches the surface of your eye with the tonometer to measure your IOP. Like NCT, applanation tonometry is painless. At most, you may feel the tonometer probe tickle your eyelashes. The whole test takes just a few seconds. You typically have no warning signs of glaucoma until you already have significant vision loss. For this reason, routine eye exams that include tonometry are essential to rule out early signs of glaucoma and protect your eyesight.