Seeing an eye doctor once is year is part of recommended health care for adults, but oftentimes people without visual issues skip this appointment. According to a recent survey, among those who have not visited an eye doctor in the past year, 33 percent say they haven’t gone because their vision is “fine.” But even so-called “perfect” 20/20 vision can mask eye issues—problems that in time could affect your vision and overall health.
“Regardless of your age or physical health, an annual comprehensive eye exam will help to detect any eye problems at their early stages when they’re most treatable,” says Dallas-based Dr. David E. Weber, O.D. “Not all eye issues affect vision, so having 20/20 vision isn’t necessarily a clean bill of eye health. An optometrist can potentially catch eye issues before they affect vision and recommend the best treatment options.”
What “perfect” vision really means
20/20 vision refers to standard visual acuity, or sharpness, measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance. “Having 20/20 vision does not necessarily mean you have perfect vision,” Weber says. “Other factors contribute to your overall visual ability including peripheral awareness, eye coordination, depth perception, focusing ability, color vision, and cognitive function.”
Testing for overall eye health
A visit to the eye doctor for a comprehensive exam tests more than just your eyesight—it tests the overall health of your eyes. In addition to determining whether you need lenses, eye doctors will check for eye diseases and systemic problems that could lead to vision loss.
Eye exams can also uncover symptoms of other health issues, sometimes before symptoms have appeared in other parts of the body. “Diabetes, high blood pressure, and some cancers can all affect the eyes and be detected through an eye exam,” Weber says.
Potential eye issues
Besides checking your vision and prescribing glasses or contact lenses, eye doctors check for different eye diseases.
Here are symptoms of common illnesses:
- Cataracts. Decrease in the quality of vision, sometimes described as looking through cloudy glass, as well as increased sensitivity to the glare of sunlight, bright lights or headlights at night, and reduced color vision.
- Glaucoma. Glaucoma is commonly an asymptomatic disease: a patient will not detect a loss of their peripheral vision until later in the disease process. A less common emergency form of glaucoma may bring sudden blurry vision with halos around lights and eye pain—even nausea and vomiting.
- Retinal detachment. Sudden visual disturbance centrally and/or peripherally including the appearance of spots and flashing lights.
- Macular degeneration. Slow, painless loss of vision, shadowy areas in central vision and/or unusually fuzzy or distorted vision. In rare cases, macular degeneration can cause a sudden loss of vision.
- Digital eye fatigue. Eye strain, blurred vision, headaches, and neck and shoulder pain.
- Diabetic retinopathy. Blurred vision, “floaters” or spots in vision, severe vision loss and/or blindness.
The comprehensive eye exam
“Compared to a vision screening that only tests vision, a comprehensive eye exam checks for acuity as well as overall eye health,” Weber says.
Here’s what’s tested during an eye exam:
- Refraction. Determining appropriate lenses for an individual’s needs.
- Retinoscopy, aberrometry and/or auto refraction. Measuring how the eye focuses to determine nearsightedness, farsightedness, and/or astigmatism.
- Cover testing (phorometry). An assessment of eye muscle coordination for diagnosing “lazy eye” and “turned eye.”
- Slit-lamp examination. A highly magnified view of the eye’s anatomy via a bio microscope to look for diseases and physical changes.
- Tonometry. Determining intraocular pressure. Elevated intraocular pressure may be indicate glaucoma.
- Pupillary dilation. Enlargement of the pupil with eye drops to allow an expanded view of the eye’s interior. “Viewing the back of the eye is much more difficult when the pupil is not dilated,” says Dr. Christopher Quinn, O.D., president of the American Optometric Association. “In order to see the entire retina and to do a detailed examination of the optic nerve the pupil must be dilated.”
How often to see an eye doctor
Regular eye exam should be part of everyone’s health routine. Only 29 percent of adults get their eyes checked annually, though. Adults 18-60 years old with no vision problems or signs of disease should see an eye doctor once every two years, at least. Older adults should go annually.
As for kids, the AOA recommends children get their first eye exam at 6 months old, again at 3 years of age, before entering the first grade, and then every other year until age 18. “For children, eye exams can play an important role in assessing vision related to learning,” Weber says.