What to expect from your eye examination
- Questions about your general health, vision and ocular concerns and lifestyle
- Advanced digital testing of eye length, curve, thickness and pressure, including an Optomap which provides an ultra-wide view of the retina, the light-sensitive tissue lining the back of the eye
- External and internal eye health assessment to determine if diseases such as dry eye, glaucoma, cataracts, macular degeneration and diabetes are present.
- Refractive error determination and prescription for eyeglasses or contact lenses if required
- Explanation of all tests performed and results so you have a complete understanding of your current eye health and vision needs
- Therapeutic treatment for eye conditions when required
- Laser vision consultation
- Timely referral to speciality care when required
What to bring
- Current list of medications
- Health card
- Eyeglasses (over-the-counter and prescription)
- Sunglasses (non-prescription and prescription)
- Contact lenses – wear them to your appointment
- Contact lens box – to confirm the type of contact lens and prescription
Children
Children should undergo their first eye examination at six months of age and annually thereafter. Visual abilities play a key role in early development; early detection and treatment of eye conditions can significantly decrease lifelong vision impairment. Eye examinations for children and young adults 19 years of age and under are covered by OHIP.
Adults
According to the Canadian Association of Optometrists, adults between the ages of 20 and 64 should visit their optometrist at least every two years. However, depending on your risk factors for vision problems and eye diseases, your optometrist may recommend you visit more frequently.
Seniors
The Canadian Association of Optometrists suggests that adults age 65 and older, visit their optometrist annually. However, your optometrist may suggest you have your eyes examined more frequently if you have or are at risk for vision problems and eye diseases.
A comprehensive eye examinations may include any or all of the following tests and techniques in any given order to determine your ocular and overall health. If an ocular condition or concern is discovered during a comprehensive eye exam, our optometrists may conduct or refer you to more advanced eye examinations utilizing our state-of-the-art technology.
Refraction Assessment
Light waves are bent as they pass through your cornea and lens. If light rays do not focus perfectly on the back of your eye, you have a refractive error. Having a refractive error may mean you need some form of correction, such as prescription glasses, contact lenses or refractive surgery, to see as clearly as possible.
During a refraction assessment, your doctor asks you to look through a masklike device (phoropter) that contains wheels with different lenses having different visual strengths.
Assessment of your refractive error helps your doctor determine a lens prescription that will give you the sharpest, most comfortable vision.
Your doctor may use a computerized refractor to estimate your prescription for glasses or contact lenses. Or he or she may use a technique called retinoscopy. In this procedure, the doctor shines a light into your eye and measures the refractive error by evaluating the movement of the light reflected by your retina back through your pupil.
Your eye doctor usually fine-tunes this refraction assessment by having you look through a masklike device that contains wheels of different lenses (phoropter). He or she asks you to judge which combination of lenses gives you the sharpest vision.
Other forms of testing are useful for the following:
- Auto-Refraction (refractive error estimate)
- Auto-Keratometry (cornea curvature)
- Non-Contact Tonometry (glaucoma)
- Pachymetry (cornea thickness)
- Digital Retina Scan
- Tear Osmolarity Testing with TearLab for at risk patients
These tests are done by advanced imaging and scanning technologies and techniques. More about these tests can be found below under Advanced Eye Examinations.
Medical & Visual History
Your doctor will ask questions about your personal and family medical/visual history. This may reveal specific eye tests the patient should undergo.
They will also review your eye exam history, and any visible changes in your sight, your lifestyle, and any changes in your medical condition that may affect your vision. (This includes knowing all medications you’re taking).
Visual Acuity Test
Visual acuity (VA) measures the ability of the eye to distinguish shapes and the details of objects at a given distance (20 feet) using a chart similar to the one you see on your right hand side. It is important to assess VA annually in order to detect any changes in vision. One eye is tested at a time. Your near vision may also be tested using a card with letters similar to the distant eye chart. The card is held at reading distance.
Visual Field Test
The visual field test is a measure of the central and peripheral vision (“side vision”) and is used to diagnose, determine the severity of, and monitor your eye conditions. The most common visual field test uses a light spot that is repeatedly presented in different areas of your peripheral vision.
Different test types include:
- Confrontation exam: optometrist sits in front of you and asks you to cover one eye. While looking straight ahead, the patient will communicate if they see an object move into view.
- Manual testing (Tangent screen or Goldmann exam): sitting a short distance from a screen, focusing on a target at the center. You tell the doctor when you can see an object move into your peripheral vision and when it disappears.
- Automated perimetry: looking at a screen with blinking lights, you press a button each time you see a blink.
Using your responses to one or more of these tests can determine the fullness of your field of vision. If you aren’t able to see in certain areas, identifying the pattern of your visual field loss may help your eye doctor diagnose your eye condition.
Binocular Vision Test
Binocular vision assessment (ability to see using both eyes together), as it relates to eye coordination, depth perception, and eye movements, or in some cases, eye-hand coordination.
- Cover test
- Near point of convergence
- Broad H test
- Stereoacuity
Color Vision Test
Usually performed on pediatric patients or any patient when medically necessary.
Sometimes, problems with color vision are due to a disease affecting your optic nerve, such as glaucoma. Poor color vision can also be the result of an inherited problem with the cones (color-sensitive photoreceptors) in your retina. The retina is the light-sensitive layer at the back of your eye.
Certain diseases can cause color vision impairment, including:
- Diabetes
- Alcoholism
- Macular degeneration
- Leukemia
- Alzheimer’s disease
- Parkinson’s disease
- Sickle cell anemia
Your color vision may improve if you receive treatment for the underlying condition.
Slit Lamp Examination (biomicroscopy)
A slit lamp is a microscope that magnifies and illuminates the front of your eye with an intense line of light. Your doctor uses this device to examine the eyelids, lashes, cornea, iris, lens and fluid chamber between your cornea and iris. It allows the doctor to microscopically examine your eyes for any abnormalities or problems.
What does this exam help diagnose?
A slit lamp exam can help diagnose the following conditions:
- Macular degeneration, a chronic condition affecting the part of the eye that is responsible for central vision
- Detached retina, a condition when the retina, which is an important layer of tissue at the back of the eye, becomes detached from its base
- Cataracts, a clouding of the lens that negatively affects the ability to see images clearly
- Injury to the cornea, an injury to one of the tissues that covers the surface of the eye
- Blockages of the retinal vessel, obstructions in the eye’s blood vessels that can cause a sudden or gradual loss of vision
What do abnormal results mean?
If the results of your slit lamp exam are abnormal, a variety of conditions may be present, including:
- infection
- inflammation
- increased pressure in the eye
- degeneration of the arteries or veins in the eye
For example, if macular degeneration is taking place, the doctor may find drusen, which are yellow deposits that can form in the macula early on in age-related macular degeneration. If your doctor suspects a particular cause of vision problems, they may recommend further testing to get a more definitive diagnosis.
Retinal Examination (ophthalmoscopy)
A retinal examinations – sometimes called ophthalmoscopy or funduscopy – is a test that allows your doctor to look at the back of your eye. This part of your eye is called the fundus, and consists of:
- Retina
- Optic disc
- Underlying layer of blood vessels
This test is often included in a routine eye exam to screen for eye diseases. Your eye doctor may also order it if you have a condition that affects your blood vessels, such as high blood pressure or diabetes.
When is a retinal examination used?
Your eye doctor can use ophthalmoscopy to screen for eye diseases and conditions that can affect blood vessels. These conditions include:
- damage to your optic nerve
- retinal tear or detachment
- glaucoma, which is excessive pressure in your eye
- macular degeneration, a loss of vision in the center of your visual field
- cytomegalovirus (CMV) retinitis, an infection of your retina
- melanoma, a type of skin cancer that can spread to your eye
- hypertension, which is also known as high blood pressure
- diabetes
What other techniques are used?
Usually before your doctor can see these structures, your pupils must be dilated with eye drops that keep the pupil from getting smaller when your doctor shines light into the eye.
After administering eye drops and giving them time to work, your eye doctor may use one or more of these techniques to view the back of your eye:
- Direct exam.Your eye doctor uses an ophthalmoscope to shine a beam of light through your pupil to see the back of the eye. Sometimes eye drops aren’t necessary to dilate your eyes before this exam.
- Indirect exam.During this exam, you might lie down, recline in a chair or sit up. Your eye doctor examines the inside of the eye with the aid of a condensing lens and a bright light mounted on his or her forehead. This exam lets your doctor see the retina and other structures inside your eye in great detail and in three dimensions.
- Slit-lamp examination. This procedure gives your eye doctor the same view of your eye as an indirect examination, but with greater magnification.
You’ll sit with an instrument in front of you, known as a slit-lamp. It will have a place for you to rest your chin and forehead. This will help keep your head steady during your exam.
Once you’re positioned, your eye doctor will turn on a bright light in front of your eye. Then they will use a microscope to look at the back of your eye. They may ask you to look in different directions and use their finger to open your eye to get a better view. They may also apply some pressure to your eye using a small, blunt probe.
Dilated Fundus Examination
- internal examination of ocular structures, i.e. retina, optic nerve, vitreous, etc.
- patient pupils are fully dilated (using drops) to allow greater viewing area.
- performed when medically necessary for at-risk patients
Patient Counselling
- discuss examination results with and provide a strategic plan of action with a medical recommendation
- Q & A
Optical Technician Support
Transfer patient to Optical Dispensary or Optician to choose eyewear.
Advanced eye examinations may include any or all of the following tests and techniques in any given order to further determine your ocular and overall health. If an ocular condition or concern is discovered during a comprehensive eye exam, our optometrists may conduct or refer you to more advanced eye examinations utilizing our state-of-the-art technology or our partners of ophthalmology.
Corneal Mapping
Corneal topography is a computer assisted diagnostic tool that creates a three-dimensional map of the surface curvature of the cornea. The cornea (the front window of the eye) is responsible for about 70 percent of the eye’s focusing power.
An eye with normal vision has an evenly rounded cornea, but if the cornea is too flat, too steep, or unevenly curved, less than perfect vision results. The greatest advantage of corneal topography is its ability to detect irregular conditions invisible to most conventional testing.
This test can show problems with your eye’s surface, like swelling or scarring, or conditions such as astigmatism. You may have this test done before refractive surgery such as LASIK, a cornea transplant, or a contact lens fitting.
More about Corneal Mapping:
Corneal topography produces a detailed, visual description of the shape and power of the cornea. This type of analysis provides your doctor with very fine details regarding the condition of the corneal surface. These details are used to diagnose, monitor, and treat various eye conditions. They are also used in fitting contact lenses and for planning surgery, including laser vision correction. For laser vision correction the corneal topography map is used in conjunction with other tests to determine exactly how much corneal tissue will be removed to correct vision and with what ablation pattern.
Computerized corneal topography can be beneficial in the evaluation of certain diseases and injuries of the cornea including:
- Corneal diseases
- Corneal abrasions
- Corneal deformities
- Irregular astigmatism following corneal transplants
- Postoperative cataract extraction with acquired astigmatism
The corneal topography equipment consists of a computer linked to a lighted bowl that contains a pattern of rings. During a diagnostic test, the patient sits in front of the bowl with his or her head pressed against a bar while a series of data points are generated. Computer software digitizes these data points to produce a printout of the corneal shape, using different colors to identify different elevations, much like a topographic map of the earth displays changes in the land surface. The non-contact testing is painless and brief.
Digital Retinal Imaging
Digital Retinal Imaging allows your eye doctor to evaluate the health of the back of your eye, the retina. It is critical to confirm the health of the retina, optic nerve and other retinal structures.
The digital camera snaps a high-resolution digital picture of your retina. This picture clearly shows the health of your eyes and is used as a baseline to track any changes in your eyes in future eye examinations.
The advantages of digital imaging include:
- Quick, safe, non-invasive and painless
- Provides detailed images of your retina and sub-surface of your eyes
- Provides instant, direct imaging of the form and structure of eye tissue
- Image resolution is extremely high quality
- Uses eye-safe near-infra-red light
- No patient prep required
Optical Coherence Tomography (OCT Scan)
An OCT Scan is the latest advancement in imaging technology. Similar to ultrasound, this diagnostic technique employs light rather than sound waves to achieve higher resolution pictures of the structural layers of the back of the eye.
A scanning laser used to analyze the layers of the retina and optic nerve for any signs of eye disease. It works using light without radiation, and is essential for early diagnosis of glaucoma, macular degeneration and diabetic retinal disease.
With an OCT scan, doctors are provided with color-coded, cross-sectional images of the retina. These detailed images have revolutionized early detection and treatment of eye conditions such as wet and dry age-related macular degeneration, glaucoma, retinal detachment and diabetic retinopathy.
An OCT scan is a non-invasive, painless test. It is performed in about 10 minutes right in our office.
The advantages of digital imaging include:
- Quick, safe, non-invasive and painless
- Provides detailed images of your retina and sub-surface of your eyes
- Provides instant, direct imaging of the form and structure of eye tissue
- Image resolution is extremely high quality
- Uses eye-safe near-infra-red light
- No patient prep required
Please contact our office to inquire about an OCT at your next appointment.
Screening for Glaucoma
To diagnose glaucoma, your doctor will want to perform a comprehensive eye examination. They will check for signs of deterioration, including loss of nerve tissue.
Tonometry measures the fluid pressure inside your eye (intraocular pressure). This is one test that helps your eye doctor detect glaucoma, a disease that damages the optic nerve.
Your Optometrist may also use one or more of the following tests and procedures:
- Applanation Tonometry. This test measures the amount of force needed to temporarily flatten a part of your cornea.
- You will be given eyedrops with fluorescein, the same dye used in a regular slit-lamp examination. You will also receive eyedrops containing an anesthetic.
- Using the slit lamp, your doctor moves the tonometer to touch your cornea and determine the eye pressure. Because your eye is numbed, the test does not hurt.
- Noncontact Tonometry. This method uses a puff of air to estimate the pressure in your eye. No instruments touch your eye, so you will not need an anesthetic.
- Pachymetry Test. If your eye pressure is higher than average, or your optic nerve looks unusual, your doctor may use a pachymetry test.
- This test uses sound waves to measure the thickness of your cornea. The most common way of measuring corneal thickness is to put an anesthetic drop in your eye, then place a small probe in contact with the front surface of the eye. This measurement takes seconds.
- Visual Field Test (Perimetry Test). This test can tell your doctor if glaucoma is affecting your vision by measuring your peripheral vision, side vision and your central vision.
- Monitoring Your Optic Nerve. If your doctor wants to monitor for gradual changes to your optic nerve, they may take photographs of your optic nerve to conduct a side-by-side comparison over time.
You may need more-specialized tests, depending on your age, medical history and risk of developing eye disease.
Heidelberg Retinal Tomography (HRT scan)
Heidelberg Retinal Tomography is a diagnostic procedure used for precise observation and documentation of the optic nerve head, essential for the diagnosis and management of glaucoma. The HRT uses a special laser to take 3-dimensional photographs of the optic nerve and surrounding retina. This laser, which will not harm the eye, is focused on the surface of the optic nerve and captures the image.
The HRT takes images of deeper and deeper layers until the desired depth has been reached. Finally, the instrument takes all these pictures of the layers and puts them together to form a 3D image of the entire optic nerve.
The typical optic nerve damage that occurs in glaucoma is known as “cupping.” As the cells making up the nerve die, due at least in part increased pressure inside the eye, they die and disappear.
When sufficient numbers of these cells are gone, they leave behind a small “cup” in the nerve. So one important thing doctors look for when they examine the optic nerve is the presence and extent of the “cup,” how deep and wide it is.
The HRT image can be used to compute things such as the area of the optic disc, the volume of the cup, and the area of the rim around the cup. Over several visits, scans are layered and changes are measured.
