The parts of a comprehensive eye examination vary according to the patient's age, date of last exam, and other factors. Not all parts of the eye exam may be needed or performed, but the first part of the eye exam will include documenting medical history. Here are some eye and vision tests that are likely to be encountered during a comprehensive eye exam:
Visual acuity tests measure the sharpness of vision and are usually performed using a projected eye chart to measure the distance visual acuity and a hand-held small acuity chart to measure the near vision (for reading).
A screening test that checks the colour vision is performed on every child's first eye exam to rule out color blindness or deficiency.
A test used to assess strabismus/squint or a more subtle binocular vision problem that could cause eye strain or amblyopia (lazy eye).
Ocular motility testing is performed to determine how well eyes can follow a moving object and/or quickly move between and accurately fixate on two separate targets.
This is used to test perception of depth and 3-dimensional structure obtained on the basis of visual information deriving from two eyes by individuals with normally developed binocular vision.
This test may be used to estimate which lens powers will best correct distance vision. Based on the way the light reflects from the eye, the optometrist is able to obtain an approximation of the eyeglass prescription. This test is useful for children and patients who are unable to accurately answer the optometrists's questions.
This is the test used to determine the exact glasses prescription. This may be done with a manual phoropter/refractor head or a digital one the optometrist can use remotely while seated.
Autorefractor or aberrometer may be used to automatically estimate the spectacle prescription. This is helpful for determining an spectacle prescription for young children and other patients who may have trouble sitting still, paying attention and providing the feedback that the doctor needs to perform accurate manual refraction. They also save time as they take only a few seconds.
A slit lamp is a binocular microscope (or biomicroscope) used to examine the structures of the eye under high magnification, including eyelids, cornea, conjunctiva, iris, and lens. With the help of a hand-held lens, the doctor may also use the slit lamp to examine structures located farther back in the eye, such as the retina and optic nerve.
The slit lamp exam can be used to detect a wide range of eye conditions and diseases, including cataracts, macular degeneration, corneal ulcers, and diabetic retinopathy, etc.
Testing for glaucoma typically begins with measuring the pressure inside the eyes. This can without an air puff test and the machine calculates intraocular pressure (IOP). High eye pressure patients may be at risk for or have glaucoma. The test is completely painless.
To obtain a better view of the eye's internal structures, the optometrist may need to instill dilating eye drops to enlarge the pupils which usually takes about 20-30 minutes to start working. When pupils are dilated, eyes will be sensitive to light (because more light is getting into the eyes) and you may notice difficulty focusing on objects up close. These effects can last for several hours, depending on the strength of the drops used.
Digital images will be taken of the retina - the back part of your eye. There is no need to have the pupils dilated for this test. The optometrist will review these images with you and store the images on your patient record. At each visit, new images will be taken and compared to the previous years to check for any changes to the retina.
A comprehensive eye exam can take up to an hour, depending on the number and complexity of tests required to fully evaluate vision and the eyes health. If the eyes are dilated, at least a 90-minute appointment should be planned.
It important to remember that eyes will be sensitive to light and vision may be blurry and you should wear sunglasses after your exam. Driving after dilation is not recommended.
For your safety, if you do not feel comfortable driving, arrange for someone to drive you home.