The purpose of a routine eye exam is for checking your vision, screening for eye disease(s), updating eyeglasses and/or contact lens prescriptions. A routine eye exam will provide a final diagnosis; like nearsightedness, farsightedness or astigmatism, as well as any medical diagnoses.
Periodic eye and vision examinations are an important part of preventive health care. Many eye and vision problems have no obvious signs or symptoms, so you might not know a problem exists. Early diagnosis and treatment of eye and vision problems can help prevent vision loss.
Each patient’s signs and symptoms, along with your optometrist’s professional judgment, will determine what tests your optometrist conducts. A comprehensive adult eye and vision examination may include, but is not limited to, the following tests.
Patient History: The doctor will ask about any eye or vision problems you are currently having and about your overall health. In addition, a patient history will include when your eye or vision symptoms began, medications you are taking, and any work-related or environmental conditions that may be affecting your vision. The doctor will also ask about any previous eye or health conditions you and your family members have experienced.
Visual Acuity with the eye chart: Visual acuity measurements evaluate how clearly each eye is seeing. Reading charts are often used to measure visual acuity. As part of the testing, you will read letters on charts at a distance and near.
The results of visual acuity testing are written as a fraction, such as 20/40. The top number in the fraction is the standard distance at which testing is done (20 feet). The bottom number is the smallest letter size you were able to read. A person with 20/40 visual acuity would have to get within 20 feet to see a letter that should be seen clearly at 40 feet. Normal distance visual acuity is 20/20.
Other Preliminary Tests you may or may not have include:
Evaluations of depth perception, color vision, eye muscle movements, peripheral or side vision, and the way your pupils respond to light.
Keratometry/Topography: This test measures the curvature of the cornea (the clear outer surface of the eye) by focusing a circle of light on the cornea and measuring its reflection. This measurement is particularly critical in determining the proper fit for contact lenses.
Refraction eye exam with the phoropter: A refraction determines the lens power you need to compensate for any refractive error (nearsightedness, farsightedness or astigmatism). Using an instrument called a phoropter, you will have a series of lenses placed in front of your eyes. The lens power is then refined based your input on the lenses that give you the clearest vision.
This testing can be done without eye drops to determine how the eyes respond under normal seeing conditions. However, eye drops may be used with patients who can’t respond verbally or when some of the eyes’ focusing power may be hidden. The drops temporarily keep the eyes from changing focus during testing.
Eye Focusing and Eye Movement Testing: To see a clear, single image, the eyes must effectively change focus, move and work in unison. An assessment of accommodation, ocular motility and binocular vision determines how well your eyes focus, move and work together. This testing will look for problems that keep your eyes from focusing effectively or make using both eyes together difficult.
Eye exam: A wide variety of microscopes, lense, and digital technology will be used to assess the health of all the structures of the eye and the surrounding tissues. Dilating eye drops are often used to temporarily widen the pupil for better views of the structures inside the eye. In addition to measuring the pressure inside of the eye, this also the part of the eye exam where your doctor of optometry can detect otherwise unknown eye and systemic diseases.
Supplemental testing: Additional testing may be needed based on the results of the previous tests to confirm or rule out possible problems, to clarify uncertain findings, or to provide a more in-depth assessment.
At the completion of the examination, you will be assessed and evaluate the results of the testing to determine a diagnosis and develop a treatment plan. You will have the nature of any visual or eye health problems found and explain available treatment options. In some cases, referral for consultation with, or treatment by, another health care provider may be indicated.
If you have questions about any diagnosed eye or vision conditions, or treatment recommendations, don’t hesitate to ask your doctor for additional information or explanation.