If you have no known eye problems, The American Academy of Ophthalmology recommends that you have a baseline eye examination at age 40. A baseline screening can help identify signs of eye disease at an early stage when many treatments may have the greatest impact on preserving vision.
Many eye diseases are inherited so if you have family history of eye disease, or if you have a medical condition that puts you at greater risk for eye disease such as diabetes or high blood pressure, you should not wait to have a comprehensive eye exam. Once you’ve had an exam, your OCB eye doctor will recommend how often you should return for eye examinations. It is recommended for patients 65 or older to have yearly eye exams. This is especially important for early detection of certain age-related eye diseases such as cataracts, glaucoma and macular degeneration.
A comprehensive eye exam is relatively simple and comfortable. You can expect your eye doctor to check the following:
Your medical history. Your doctor will ask you questions related to your vision and overall health. It is important to note any family medical history as well, which can play a role in early detection for certain diseases that are inherited.
Your visual acuity. This is a measure of the eye’s ability to see an image at a certain distance. To determine visual acuity, a standard eye chart is used. The test is performed on one eye at a time. A measurement of 20/20 vision is a term used to express normal visual acuity. In 20/20 vision, individuals can see at 20 feet clearly what most individual with normal vision can see at 20 feet. If for example, your vision is 20/40, that means you can see at a 20 foot distance what a person with normal vision can see at 40 feet. If the test shows that you need corrected lenses or an adjustment in your current prescription, you may be asked to view an eye chart through a device called a phoropter, which contains different lenses. The phoropter can help determine the best eyeglass or contact lens prescription to correct any refractive error you may have.
Your pupils. Your OCB eye doctor or ophthalmic technician will check your pupils by shining a bright beam of light into them. Pupils should become smaller (constrict.) In some cases, pupils widen (dilate) which may be indicative of an underlying concern.
Visual fields. This test looks at peripheral vision, or your side vision. Most people don’t recognize on their own when they’ve lost peripheral vision, which makes this test very important because loss of side vision may be a symptom of glaucoma. This test can be performed manually. In this case your doctor or technologist will hold an arm to either side holding up a finger or holding an object such as a pen at the outer edges of your visual fields and ask you when you see it. The doctor may also recommend a Humphrey Visual Field test, a computerized test that measures peripheral vision.
Ocular motility (eye movement). This is a test of eye muscle function. Your eye doctor will want to see how easily your eyes move in all directions, how well they can track objects and how your eyes align with each other.
Intraocular eye pressure (IOP). This test, called tonometry, measures the pressure within your eye. An elevated IOP is a sign of glaucoma. Numbing drops may be used for your comfort.
The front part of your eye. A type of microscope called a slit lamp is used to illuminate the front part of the eye, including the eyelids, cornea, iris and lens. As you keep your head steady on a chin rest, a beam of light is projected onto and into your eye. The slit lamp uses a narrow light beam and magnification to see a cross sectional picture of the eye. This can reveal whether you are developing cataracts or have any scars or scratches on your cornea. It also enables the doctor to detect the presence of foreign particles in the cornea and inflammation in the anterior chamber of the eye.
Your retina and optic nerve. Your OCB eye doctor will put drops in your eye to dilate your pupil. This will allow him or her to thoroughly examine your retina and optic nerve, located at the back of your eye, for signs of damage. Your eyes might be temporarily sensitive to light for a few hours after they are dilated, making it difficult to drive. This is why it is important to arrange for a family member or friend to drive you home from your eye exam.
Your OCB eye doctor may suggest additional testing to further examine your eye using specialized imaging techniques such as OCT (optimal coherence tomography), topography or fundus photos. These tests can be crucial in diagnosing a disease in its early stages.