Eye Exam and a Sight Test
In some provinces, many optical stores offer sight tests or vision tests using automated machinery. This is not the same exam you will get from an eye doctor. Let’s explore the differences between an eye exam and a sight test.
Basic Differences
A sight test isn’t a proper eye exam and isn’t done by a trained, licensed professional. On the other hand, an eye doctor can examine, diagnose, treat, manage and help to prevent diseases and disorders affecting your eyes and their related structures. They also check your prescription and prescribe eyewear. In most provinces, eye doctors can also prescribe medications to treat eye conditions like infections, inflammations, allergies and injuries.
Sight Tests
A sight test determines lens power by relying on a combination or computerized tests using automated equipment. Comprehensiveness and accuracy is limited. Some things a sight test doesn’t account for are as follows:
- Eye muscle coordination
- Eye fixation and alignment
- Pupil size
- Corneal or lens irregularities
- Patient movement and attention
Also, something called instrument myopia can influence test results. This problem is created by the eye’s tendency to over-focus when looking through a machine and that can lead to an inaccurate measurement of refraction.
A sight test overlooks many serious eye problems and diseases because the eye itself is not examined. Some eye and health conditions that can’t be detected by a sight test include:
- Glaucoma can be caused by elevated pressure within the eye, which can lead to damage to the optic nerve that carries visual information to the brain. If not detected and treated at an early stage, eventually serious vision loss occurs.
- Diabetic retinopathy is a weakening or swelling of the tiny blood vessels in the retina and the growth of new blood vessels resulting in blood leakage and other changes. Left untreated diabetic retinopathy can result in blindness.
- Brain tumors – cancerous or non-cancerous (benign);
- Eye tumors
- High blood pressure can lead to stroke or heart attack, as well as other health problems.
- Retinal detachment is a condition where the retina peels away from the back of the eye, either partially or completely. When this happens, some degree of vision loss occurs because the retina stops working; light signals can’t get back to the brain to be processed. Vision loss can be severe and permanent, depending on the severity of the detachment.
Eye Exam
An eye exam is performed by a Doctor of Optometry who looks at the entire eye and visual system. An eye exam could be called a physical for your eyes and it can detect eye diseases and disorders in their early stages when treatment options work best.
Although eye doctors may use automated computerized instruments to provide an estimate of the prescription, they also use their extensive training and experience, along with professional judgment, to direct testing and interpret results. This is the only way an accurate prescription can be determined and customized to fit a patient’s needs.
