Understanding Your Prescription


You may not realise it, but optometrists use a wide variety of tests and procedures to examine your eyes. These tests range from reading an eye chart to complex tests using high-powered lenses to visualize the tiny structures inside of your eyes.


Before you even enter the testing room, you will usually be taken to a pre-testing area to use two pieces of equipment.

One is an Optomap image which is fast, painless and comfortable. Nothing touches your eye at any time and it is suitable for the whole family. To have the exam, you simply look into the device one eye at a time (like looking through a keyhole) and you will see a comfortable flash of light to let you know the image of your retina has been taken.

Under normal circumstances, dilation drops might not be necessary, but your eye care practitioner will decide if your pupils need to be dilated depending on your conditions. The capture takes less than a second. Images are available immediately for review AND you can see your own retina. You see exactly what your eye care practitioner sees - even in a 3D animation.

The visual field test is a subjective measure of central and peripheral vision, or “side vision,” and is used by your doctor to diagnose, determine the severity of, and monitor your glaucoma. The most common visual field test uses a light spot that is repeatedly presented in different areas of your peripheral vision.

In some opticians, you may find the Optometrist using a different Glaucoma test in their room. More commonly though this is done as part of the pre-test before the main eye examination. This test is important as typically you have no warning signs of glaucoma until you already have significant vision loss. For this reason, routine eye exams test for this to rule out early signs of glaucoma to protect your eyesight.

The Eye Examination

Once in the test, the optometrist will ask various questions, even if you have been seeing the same Optometrist for years, to understand your any progressive symptoms from previous history you may have. Your optometrist will ask why you are having your eyes examined, whether it is a routine check-up, or if you have come for a specific reason.

If you are experiencing problems with your eyes or vision, your optometrist will need to know what symptoms you have, how long you have had them and whether any changes have happened suddenly or slowly over a period of time. They will also need to know about your general health including any medication you are taking, whether you suffer from headaches, or have any close relatives with a history of eye problems that they may not already be aware of.

You will also be asked about your previous glasses or contact lenses. In addition, your occupation and hobbies such as sport can influence the type of lenses that are beneficial to your suited lifestyle.

A comprehensive eye exam evaluates your vision and the health of your eyes. There are various eye and vision tests that you are likely to encounter during your eye exam. You will be asked to look at the Snellen eye chart. This is the most known part of the test that everyone associates with an eye examination, looking at the letters ranging from very large at the top, to the tiny letters right at the bottom. Further tests determine your visual acuity, measuring the sharpness of your vision to get pin point accuracy in your final prescription. Sometimes a small hand held acuity chart is used to measure near vision also.

When your optician covers one eye at a time they are checking to see how your eyes work together in focusing on objects across the room, then on objects close to you. The optometrist can the examine how well your eye moves to pick up and focus on a fixed object.

Retinoscopy is where your optometrist obtains an approximation of your eyeglass