A comprehensive eye exam is a special diagnostic process that evaluates vision and the overall health of the eyes. It involves a wide range of tests including things like reading a simple eye chart, examining the structures inside the eyes as well as other special diagnostic procedures. A comprehensive eye exam can take up to an hour to complete.
What Tests Are Performed In A Comprehensive Eye Exam?
Several different diagnostic processes are bundled into a comprehensive eye exam. The following is an overview of tests and what to expect.
Visual Acuity Test
A visual acuity test uses a basic eye chart. You will be asked to read a different line at a specified distance. This will help your eye doctor assess the sharpness of your vision.
Color Blindness Test
This is a special screening process that your eye doctor will use to check your perception of color. Color blindness is often hereditary. So, let your physician know if any of your immediate family members have a history of being color blind or have abnormalities in their ability to perceive color. Though some eye health problems can cause color blindness without a genetic connection.
This is one of the first diagnostics in a comprehensive eye exam. The lights in the room will be dimmed and you will be asked to focus on a large target like the letter E at the top of a standard eye chart. The eye doctor will then shine a light at each eye as they flip through various lenses. This helps evaluate whether or not you need corrective lenses.
A refraction test typically follows a retinoscopy test. It’s designed to detect if you have hyperopia known as farsightedness, myopia which is also known as nearsightedness, as well as potential astigmatism and presbyopia.
If you do need prescription eyeglasses or contact lenses, it will assess the power you need to properly correct your vision. During this diagnostic, your eye doctor places a phoropter instrument in front of your eyes as they show you a series of lens choices. You will then be asked if each lens is helping to make your vision better or worse.
Autorefractors & Aberrometers Evaluation
If you do need eyeglasses your eye doctor will likely use an autorefractor or an aberrometer to quickly determine the prescription you need. This process calls for you to stabilize your head by placing your chin on a static rest. You will then look into the autorefractor or aberrometer at a small pinpoint of light.
The autorefractor will determine the lens power needed to accurately focus light on the retina deep inside your eye. This process only takes a few seconds. The aberrometer employs sophisticated wavefront technology to detect vision errors.
Testing Eye Alignment With A Cover Test
With this test, your eye doctor will examine the alignment of each eye and how they work together with a simple cover test. Then they will ask you to focus on a small object across the room, then alternatively cover each of your eyes. They will then repeat this test with a closer object.
This diagnostic can be used to help detect conditions like strabismus, eye strain, or amblyopia, which is sometimes referred to as a lazy eye.
An Ocular Motility Test
This is a special diagnostic that’s designed to evaluate the ability of your eyes to follow a moving object. It also assesses your ability to change focus between two separate targets. During the process, your eye doctor will ask you to hold your head still, while you follow a handheld light or some other type of target.
An ocular mobility test will help to assess the eye movements and things like eye strain that might also impact your ability to read and other skills that call for moving focus or following objects.
Stereopsis Test To Test Depth Perception
Testing your ability to accurately perceive three-dimensional objects and distance calls for a special stereopsis test. This process calls for you to wear a pair of 3-D glasses while you stare at a booklet of test patterns made up of small circles. You will then indicate which circle looks the closest.
Slit Lamp Exam
This test uses a binocular microscope called a Biomicroscope to examine the structures of your eye at high magnification. It is a very effective diagnostic for detecting a wide range of conditions that can affect the eyes as well as certain diseases. This includes cataracts, macular degeneration, corneal ulcers, and eve diabetic retinopathy, to name a few.
During this phase of the exam, you will place your forehead and chin securely on the rests at the front of the instrument. Then the eye doctor will carefully examine the structures of the front of your eyes. This includes your eyelids, cornea, conjunctiva, and iris, as well as the lens.
A glaucoma test essentially measures the pressure inside each of your eyes. It starts with a non-contact tonometry test, which is also known as an NCT. It calls for you to put your chin on a static chin rest. You then look at the light inside the machine as a gentle burst of air is blown at your open eyes.
The resistance to the puff of air is then precisely measured as the machine calculates the intraocular pressure inside each eye. If the NCT reveals high intraocular pressure, you might be at increased risk of glaucoma.
Another test might also be performed, where an applanation tonometer is mounted on a slit lamp. The doctor will then tint your eyes with a yellow eye drop. This will also serve to numb the eye and might also make your eyes feel a little heavy. The dye will glow under blue light, as your eye doctor carefully touches the surface of each eye with the tonometer.
Pupil Dilation Test
With this diagnostic, your eye doctor will use special eye drops that dilate your pupils. It tends to cause light sensitivity, so the dilation test is usually performed at the end of the comprehensive eye exam. It typically takes around half an hour to fully dilate your pupils and can take two hours or more to fully wear off. Your physician might recommend bringing a pair of strong sunglasses with you and having someone drive you home.
Once your pupils are fully dilated your eye doctor will use an array of instruments to look inside your eyes. This allows your eye doctor to evaluate several different structures in your eye. Most importantly the retina. It might also be performed in conjunction with a retinal imaging scan to capture eye resolution images of the retina.
Visual Field Test
If your eye doctor is concerned that you have developed scotomas or blind spots in your vision, they might also want to perform a visual field test. This might be performed as part of a glaucoma test