An online eye test may seem like a convenient way to check your vision or get an eyeglass prescription but beware, these tests aren’t all they are chocked up to be. In fact, it's important to understand they may be dangerous.
What is an online eye test really testing?
An online eye test is actually not an eye test at all but just a vision or sight test - and a partial test at that. It is designed to measure your visual acuity and refractive error (nearsightedness, farsightedness or astigmatism) and to determine an eyeglass prescription - which is the spectacle lens power needed to correct the refractive error in your vision.
Given that there is no one with medical training actually performing or checking the accuracy of the test, it is questionable how well the exam does even this. In fact, when an eye doctor does a refraction for glasses or contact lenses it also involves some judgement on the doctor’s part. The eye doctor will often adjust the prescription slightly based on the patient’s age, occupation or hobbies. The doctor may prescribe a prism in the lenses to help with binocularity (the way that the eyes work together as a team) and to prevent double vision in those who have deviations of the eye. There is no way an online exam can do any of this.
Further, a refraction is only one very small part of an eye exam and if it takes the place of a regular comprehensive eye exam by an eye doctor, you put your eyes and vision potentially at serious risk.
A Comprehensive Eye Exam - Where Online Tests Fail
Even if your eyes see clearly and you have 20/20 vision, there may still be vision problems or eye disease present; even without pain, blurred vision or other symptoms. What the online eye test fails to measure is your complete visual health and capacity (beyond just visual acuity), the curvature of the eye (which is needed for accurate lens prescriptions- especially for contact lenses) and an assessment of the health of the eye itself.
Just as we need regular medical and dental checkups as a part of preventative health care to prevent disease and maintain our health, we also need regular eye exams. A vision test does not suffice. A comprehensive eye exam will examine much more than just how well you see. It can also check for visual processing, colour vision, depth perception and proper eye movement. It will measure your eye pressure, examine the back of your eye and look for early signs of eye disease or conditions such as glaucoma, macular degeneration, diabetes, tumours and high blood pressure - many of which threaten your eyes and vision if not caught early.
If you have some vision loss, the eye doctor will be able to determine if there is any serious underlying problem that is causing the disturbance in your vision. If you don’t have symptoms that doesn’t mean there isn’t a problem. Many serious eye conditions develop gradually without any symptoms. Some eye diseases do not affect the macula, and therefore you may still have good central vision even though there is a problem (such as glaucoma, early dry macular degeneration, early cataract, diabetes, blood pressure and even tumours). Many of these conditions threaten your eyes and even general health if not caught early and when undetected they can cause permanent and irreversible damage to your vision
Eye exams are the best way to detect these early and treat them before they develop into serious eye problems.
Whether online vision tests are inaccurate, misleading or simply insufficient, they can fail to provide essential information and can delay or prevent vision saving treatments. Additionally, you could be walking around with the wrong prescription which can cause unnecessary eye strain, headaches and difficulty doing visual tasks.
Will an Online Eye Test Really Save you Money?
Quite simply, no. Besides the fact that most eye exams are covered by OHIP or supported by third party insurance, the eye exam you are getting from an eye doctor is much more thorough and comprehensive than an online eye test, so you are not comparing apples to apples. The eye doctor’s exam uses real equipment and performs a complete and professional evaluation of your vision and eye health. There is simply no comparing this to a self administered test on a computer screen.
An online eye test may be touted as a time and money saving convenience however, this is hardly the case. An eye exam is a medical procedure that requires training, precision, and proper equipment. Anything less can put your eyes and vision at serious risk. Please reach out to us if you have any questions.