Routine eye exams are very important to monitor the health of your eyes, as well as to determine your need for glasses. Some eye diseases, such as glaucoma, have no early warnings and can only be detected with a thorough eye exam. This is why it is important to have your eyes examined every 1 – 2 years. Even if your eyes are healthy, you should still have a regular eye exam to detect any problems as soon as possible and begin necessary treatment.
Depending on your medical status and your chief complaint, your eyes may be dilated. If they are dilated, your eyes may be sensitive to light and your near vision may be blurry for about 3 – 4 hours. It is a good idea to bring sunglasses with you or we can provide you with complimentary disposable ones if needed. Also, we recommend that you bring someone with you who can drive you home after the exam. Please bring any prescription glasses, such as computer and reading glasses with you.
Here are vision tests that you are likely to encounter during a routine comprehensive eye exam:
A patient history helps to determine any symptoms the individual is experiencing, when they began, the presence of any general health problems, medications taken and occupational or environmental conditions that may be affecting vision. The doctor or ophthalmic assistant will ask about any eye or vision problems you may be having and about your overall health. The doctor will also ask about any previous eye or health conditions of you and your family members.
Reading charts are often used to measure visual acuity. Visual acuity measurements evaluate how clearly each eye is seeing. As part of the testing, you are asked to read letters on distance and near reading charts. The results of visual acuity testing are written as a fraction such as 20/40.
When testing distance vision, the top number in the fraction is the standard distance at which testing is done, twenty 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 of a letter that should be seen at 40 feet in order to see it clearly. Normal distance visual acuity is 20/20.
Eye Focusing, Eye Teaming, and Eye Movement Testing
Assessment of accommodation, ocular motility and binocular vision determines how well the eyes focus, move and work together. In order to obtain a clear, single image of what is being viewed, the eyes must effectively change focus, move and work in unison. This testing will look for problems that keep your eyes from focusing effectively or make using both eyes together difficult.
Eye Health Evaluation
A truly comprehensive eye exam almost always includes eye dilation—the addition of special eye drops that “open up” the pupil at the front of the eyeball. This allows for a maximum amount of light to enter the eyeball, giving your eye doctor the best possible visibility during a variety of specific eye tests.
Eye dilation is common during an eye exam after preliminary testing of visual acuity, pressure testing, and any vision-correction measurements have been taken. Your eyes are dilated using special drops, by far the most effective way to examine the structures inside the eye, and the light-sensitive retina at the back of the eye.
Most eyecare professionals agree: eye dilation is a critical component of a comprehensive eye exam, and vital to the detection of symptoms of eye disease like macular degeneration, diabetic eye disease, glaucoma, cataracts and more.
Having your eyes dilated doesn’t hurt—it just feels a little strange. Your pupil at the front of your eye automatically adjusts to light intensity, closing when light is more intense and opening in lower lighting conditions—much like an automatic camera adjusts to take photos indoors or outdoors.
The drops used to dilate your eyes don’t wear off immediately, that’s why it’s recommended you bring sunwear with you to a comprehensive eye exam. And if you’re driving, you may want to consider having a friend with you to help you drive home, or assist you if you feel slightly disoriented.
It is at this time your intraocular pressure (eye pressure) will be taken as well. Elevated pressure in the eye signals an increased risk for glaucoma.
Measurement of pressure within the eye is performed. Normal eye pressures range from 10 to 21 millimeters of mercury (mm Hg), averaging about 14 to 16 mm Hg. Anyone with eye pressure greater than 22 mm Hg is at an increased risk of developing glaucoma, although many people with normal pressure also develop glaucoma.