During an eye test, many aspects of vision are assessed, not only to determine how well the eyes see, but how hard the eyes are working to see. A Snellen chart, which contains rows of letters starting with one huge letter then groups of letters getting progressively smaller, is used for visual acuity. An optometrist will establish how well you see without spectacles or contact lenses by getting you to read letters until they are too small or blurred to be recognised. They test each eye on its own and both together. Then the test is repeated while wearing your existing eye wear, this is known as your best corrected vision. Then the optometrist will ask you to remove your eye wear again and will see if your ability to read letters can be improved using lenses of different strengths for each eye until your eye sight is as good as it can be. If these new lenses are a different strength from your current spectacles you are given a new prescription and new lenses will be made for you. If there is a refractive error e.g. short sightedness (myopia), long sightedness (hyperopia) or astigmatism, it means the eyes don't focus properly. This is corrected by placing an external lens, spectacle lens or contact lens, in front of the eye so that what is seen reaches the correct area on the retina in the back of the eye. This makes the eyes see as clearly as possible. Other tests will be performed to look for other conditions, such as testing that the two eyes work together properly (binocular vision), so an optometrist can find a corrective lens that gets a person’s sight near to, or in excess of, 20/20 vision. We use central vision to read and look at objects in front of us. We also need side or peripheral vision to see things that are above, below and to the sides. This is also assessed during an eye test as you need a good field of vision to drive a car and it is a requirement for certain professions such as the police.

It is vital children have their eyes tested early to screen for abnormalities. If there are problems like strabismus, where eyes are misaligned, or amblyopia, commonly called a lazy eye, the earlier treatment starts the better the outcome. Poor eyesight will also reduce a child’s ability to learn at home as well as at school. As well as testing for these conditions optometrists test for near and far vision; if needed, corrective glasses will make a great difference to a child’s ability to see and interact with the world. Children are also tested for colour blindness and 3-D vision.

Optometrists may recommend taking a photograph of the back of each of your eyes. These images are transferred to a computer and are filed in your electronic notes. The photos do not show the optometrist anything they will not have seen when inspecting your eye but provide a record that can be referred to at a later date. This is an effective way of monitoring any changes. At Westgate Optometrists, we have invested in a Zeiss Retinal Camera, ensuring this can be done as well as possible.

A visual field establishes how good your peripheral vision (PV) is. This is what you see above, below and to the sides when you are looking straight ahead. Generally your PV will not be as good as what is known as your central vision but it is important for driving and a good visual field is required to become a New Zealand police officer. There are many conditions that can affect your PV including high blood pressure, glaucoma, strokes, an overactive thyroid, and diabetes. In glaucoma, nerve cells in the retina are damaged and die so messages are unable to be transmitted to the brain. Remarkably up to 40% of these cells can be lost before a person becomes aware of reduced vision.

Optometrists are able to detect early signs of glaucoma even before you are aware of any symptoms. They are specifically looking for changes when doing the health check part of an eye test. Since the optic nerve can be affected by this condition, they will inspect the nerve head in each eye to see if the disc shape has changed and if there are any variations in colour. If picked up early, damage from this condition can be prevented from becoming serious and sight threatening.

The continued worsening of your child’s shortsightedness can be a worrying experience. While there is no definitive cure at the moment, there are treatment options which have been shown to be greatly effective in slowing down the progression. These can be suitable for children as young as 5 years old. Feel free to check out our website for details regarding these treatment options: www.westopt.nz/myopia-control

Night time contact lenses that allow you to see clearly throughout the day without the need for glasses or contact lens wear

In-clinic treatment of meibomian gland dysfunction - the most common cause of dry eyes

During an eye test optometrists routinely examine the internal and external structures of your eye. The optometrist will look into your eye by shining a light source through your pupil to illuminate the retina. This may take some time as the optometrist will want to ensure the fundus is viewed as completely as possible and all signs and symptoms of eye disease are noted. It is important that the causes of poor vision are determined before any treatment, including spectacles, is prescribed.

Diabetic retinopathy (DR) can be detected by systematic retinal screening. Diabetes retinal screening is funded by the DHB and some optometrists are contracted to provide the service in the community. Currently this community service is only available in the Greater Wellington Regional Area, Lakes District Health Board (DHB), Tairawhiti DHB, and Counties Manukau DHB. The aim of the service is to ensure each individual diagnosed with diabetes has received a retinal screen during the preceding 24 months and that their data is transferred to the primary care provider they are enrolled with, and DHB. Entry to this free service is by referral from your general practitioner (GP), who will know which optometrists are able to provide systematic retinal screening. If diabetic eye disease is detected by your regular optometrist, they will refer you to your GP for diabetes management. This will include regular systematic retinal screening. The majority of patients who have had diabetes for more than a decade will show signs of damage. Early detection helps as patients can be advised on changes to their diet and lifestyle to control blood sugar levels and minimise damage caused to this vital organ.

Eye injuries can range from relatively minor, for instance getting dish washing liquid in your eye, to penetrating injuries with a sharp object like scissors leading to blindness. Optometrists deal with superficial eye injuries. These are eye injuries that take 24-72 hours to heal. Eye injuries can be treated with eye drops to prevent infection and oral analgesia (painkillers) to treat pain. Optometrists will refer people with more serious eye injuries to ophthalmologists.

This includes testing for visual field as you need to meet a certain standard to be able to drive safely. There is a screening tool and a full test. The full test is given to borderline cases to ensure that drivers meet the required standards.