What takes place during pre-testing for your routine Eye Exam?

Many people are used to going through the motion of the different tests done during their eye exam visit, but many don’t know what is actually being tested. We would like to use this article to highlight some of the common tests done during pretesting.  Pretesting is usually done in a different room before the patient is ready to see the optometrist by an optometric assitant, ophthalmic technician or an optician.  Here are few of the most common eye tests done during the pretesting stage of your eye exam:

Advanced Diagnostics in Downtown Toronto

NCT (Non-contact Tonometry)

 Non-Contact Tonometry is used by eye care professionals to measure the intraocular pressure in an individual's eye. Intraocular pressure is the fluid pressure within the eye. Intraocular pressure is useful to measure because it can determine if the patient is more likely to develop glaucoma. Glaucoma is when there is damage to the optic nerve and be caused by an increased intraocular pressure. The optic nerve is responsible for transmitting images to the brain. A Non-Contact Tonometer uses a puff into the individual’s eye. It measures the intraocular pressure by the eye’s resistance to the puff.


             An auto-refractor is a computer-controlled machine that is used to provided an objective measurement of a person's refractive error and a starting point for prescription for glasses or contact lenses. Refractive error is a problem with focusing light properly onto the retina due to the shape of an individual's eye. Common types of refractive error are near-sightedness, which is when you can see objects near you clearly but object far away are not clear, and farsightedness, is when you are able to see objects far away clearly but are not able to see objects up close clearly. An autorefractor works by shining light into the eye and measuring how it changes as it bounces off the ocular fundus, which includes the retina, optic disc, macula, and fovea. An image of an object is shown to the patient moving in and out of focus and a number of measurements are taken of the reflection to determine when the eye is properly focused. When these figures are put together a level of correction needed for the patient is formed.


            Auto-keratometry measures the anterior curvature of the cornea, which is the front of the eye. This test can be taken at the same time as the auto-refractor in some cases. An image is reflected off of two points in the cornea, and the relationship between object size, size of the image reflected and distance between the object and keratometer are all utilized to get the result of a minimum and maximum curvature valued for the cornea. This measurement helps with contact lens fittings.


            Pachymetry is the process of measuring the thickness of an individual’s cornea. This measurement is taken just before the NCT is preformed. This is useful in regards to refractive surgery candidacy and certain corneal diseases.

Retinal Imaging

            Retinal imaging is an image that is taken of the inside of an individual's eye. It uses high-resolution imaging is used for the picture. This is used to assess the health of an individual’s retina. Within the picture an individual's retina, optic disk, and blood vessels can be seen. Retinal imaging is highly recommended when an individual has diabetes, since it can cause damage to the blood vessels in the retina.

To book your Eye Exam today with one of our optometrists in the Toronto Downtown area contact us at metro@360eyecare.ca.

Eye Exam/Test for Eye Pressure

As with any medical treatment, eye exams need to be performed professionally and with the least amount of discomfort. If a patient is interested in knowing how a test is performed, what it involves and what type of medical equipment will be used, he or she can speak with the doctor to get a better understanding. All of the questions patients have are relevant, and the more comfortable a patient feels, the easier it will be for the doctor to perform the procedure.

An eye pressure test is a procedure performed by an optometrist. An optometrist provides primary care such as vision testing, small correction treatments, eye exams, lens prescriptions and medication prescriptions for less invasive eye diseases such as allergies. Optometrists are trained and educated to perform different procedures using different equipment and methods. An eye pressure test is called tonometry. This test is used to diagnose glaucoma and other eye diseases. Since glaucoma has no symptoms, it is very hard to detect.

The first step in a tonometry test is usually eye drops. Eye drops help to numb the eye surface and this numbing helps the doctor get more accurate readings. Also, it helps the patient stay calm and keep his eyes still. After applying the numbing drops, a patient is ready for the procedure. Instruments used during the test measure pressure on the cornea and how it reacts. A simple screening test is the most common, and it is called air-puff. But these results are used and checked with additional tests.

There are three possible ways to measure eye pressure.

Applanation tonometry measures how much pressure is necessary to flatten the cornea. It is a simple test done after an air-puff test. To get results the doctors uses a slit lamp microscope.

Electronic indentation uses a pen-like tool to press on the cornea. This tool is gently pressed directly and can cause discomfort for the patient. It is used to check high IOP or in ocular pressure.

Pneumotonometry, also known as non-contact tonometry, is the aforementioned air-puff method. There is no direct tool contact with the cornea. Numbing eye drops are not needed since this is a noninvasive method. Again, how much pressure needed to flatten the cornea is measured. This method is used together with others since it can give results for IOP and it can show if any additional check-ups are necessary.

The tonometry result is the first indicator of glaucoma. If the reading is high it means there is glaucoma present. The desired result is a reading between 10-21 MmHG. A reading below or above indicates problems. It could mean glaucoma, eye inflammation, corneal injury or hyphema. The result of the eye pressure test will give more details and a better picture future steps that should be taken.

When To See An Eye Doctor For Glaucoma

Glaucoma is the second leading cause of blindness. It is a complicated eye disease that causes damage to the optic nerve. It is progressive and can cause a permanent loss of vision if not treated. Waiting to see an eye doctor until you start to develop symptoms is not a good idea and could cost you your sight.

Glaucoma is actually a group of diseases characterized by high pressure in the eyes. The most common type of glaucoma is called primary open-angle glaucoma and it is hereditary. Angle-closure basically means tunnel vision.

Am I At Risk?

Everyone is at risk for developing glaucoma. But some groups are at higher risk and should be aware of their risk so they can regularly see their eye doctor. African Americans, Hispanics, and Asians are at high risk. People over 60, and those who have family members with glaucoma should be checked regularly. People who use steroids or have had an eye injury are at high risk. Those with high blood pressure, or hypertension and the nearsighted are at high risk.
If you fall into one or more of these groups, you need to see an eye doctor soon and regularly. Even if you don’t fall into a high-risk group, the possibility of permanent blindness is not a risk most people are willing to accept.

Won’t I Know If I Have Glaucoma?

Glaucoma, particularly in its early stages, may present no symptoms. You’ll have no pain, at first, and the vision loss starts with your peripheral vision. You may not notice a loss of peripheral vision because the brain often compensates by making you unconsciously turn your head to see something outside your range of sight.

Don’t Wait To Feel Symptoms

The late stages of glaucoma present symptoms that include acute and sudden eye pain, and headaches behind eyes and brow. Once you feel these symptoms, it may be too late. You may have irreversible damage to the optic nerve. Other symptoms of late stage glaucoma include red eyeballs, large pupils that do not react to light, night halloes or starbursts, blurred vision around lights, and tunnel vision. Even with surgery, at this point you may have permanent blindness.

Acute-angle closure glaucoma has few signs, but swollen irises and pressure build up inside the eye may cause red eye and headaches. Sudden visual problems can also cause nausea, vomiting and severe eye pain. Emergency treatment is warranted in this case.

Glaucoma Should Not Take Your Eyesight

When should you see an eye doctor for glaucoma? As soon as possible. Don’t wait or think if you don’t feel any problems that you don’t have glaucoma. Glaucoma is the second leading cause of permanent blindness, but it doesn’t have to be. Knowing your risks, seeing your eye doctor regularly, and following your eye doctor’s instructions can preserve your sight and ensure continued health.

Why Do Eye Doctors Not Get Lasik?

If you are thinking about having Lasik surgery to correct your vision, you may wonder why your eye doctor wears glasses. While there are no absolutes, and it would be incorrect to say that eye doctors never choose Lasik, it is true that many do not opt for the procedure.

There could be any number of reasons why your eye doctor has not had Lasik surgery.

Not Everyone Is a Candidate

Some patients, even eye doctors, may want to have Lasik, but they are not good candidates for a variety of reasons.

It’s An Elective Surgery

No one needs Lasik.  It is entirely elective. The worst thing that can happen to you if you choose to have Lasik is blindness.  The worst thing that can happen if you do not have Lasik is you’ll have to wear glasses or contacts the rest of your life.


Eye Doctors Need To See Differently Than Most of Their Patients

Optometrists spend a good deal of their time peering into microscopes or examination equipment that requires them to depend on stereoscopic vision. Stereoscopic vision means to see a single perception of a slightly different image from each eye. Lasik may weaken three-dimensional perceptions that for some people are of no concern. But eye doctors could very well not be able to do their jobs anymore if they lose this type of vision. They may not think the benefit is worth it.

Lasik Is Not For Everyone, Even Your Eye Doctor

The decision to have Lasik surgery is unique to every individual, even your own eye doctor. If you are thinking of Lasik, but wonder why your own doctor wears glasses, talk to him about it.  Ask him if he’s ever considered it, and if he opted not to, why? His answer may surprise you.  It may make you rethink undertaking the surgery. Or it very well might not change your mind, and you’ll learn more about Lasik than you thought you knew.

Retinal Imaging

Metro Eye Care offers digital retinal imaging when you visit us for your eye examination. These images in some cases can take place of the pupil dilating drops. With this new technology, digital retinal imaging provides your optometrist with detailed images of the back of your eye. Our software (a digital retinal scanner) allows your optometrist to store, review and enhance the images of your eye to clearly record your current eyes’ health. Future photos can be compared to detect any changes to your retina at the time of your next scheduled eye examination.

Our office strongly encourages the use of this new technology as an integral tool in determining eye health status as well as creating a detailed permanent record of the condition of your eyes. Your optometrists at Metro Eye Care have invested in this latest technology because we are committed to providing you with the highest standard of eye care available.

These photos are recommended to all patients, especially patients who are at a high risk of eye disease. Patients who are at a high risk for eye disease are people living with Glaucoma, Diabetes and Macular degeneration as well as a variety of other eye diseases. These photos are also highly recommended to patients with a family history of the above mentioned conditions and can be used as a preventative measure.

Healthy retina image from Metro Eye Care

Healthy Retina

Avoid unhealthy retinas at Metro Eye Care

Unhealthy Retina