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, they may even 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 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 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 at serious risk.

A Comprehensive Eye Exam – Where Online Tests Fail

Even if the 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.

We require routine eye exams as part of preventative health care, just as we require routine dental and medical examinations to avoid illness and preserve our health. A visual examination is insufficient. A thorough eye exam will look at much more than your visual acuity. Additionally, it will assess eye movement, color vision, depth perception, and visual processing. It will check the back of your eye, measure your eye pressure, and check for early indicators of eye diseases or illnesses like glaucoma, macular degeneration, diabetes, tumors, and high blood pressure—many of which can endanger your eyesight if not detected in time.

The doctor will be able to identify any major underlying issues that may be causing your vision disruption if you do have some vision loss. Even if you don’t have any symptoms, there may still be an issue. Numerous severe eye disorders appear gradually and without any signs. Certain eye conditions, such glaucoma, early dry macular degeneration, early cataract, diabetes, blood pressure, and even tumors, may not impact the macula, so you may still have adequate vision despite the issue. Many of these problems can cause irreversible and permanent damage to your vision if they are not recognized in time, endangering your eyes and potentially your general health.

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 vision prescription which can cause unnecessary eye strain, headaches and difficulty.

Will an Online Eye Test Really Save you Money?

No. You are not comparing apples to apples since, in addition to the fact that the majority of eye exams are covered by insurance, an eye exam performed by an eye doctor is far more extensive and complete than one conducted online. Your eyesight and eye health are thoroughly and expertly evaluated by the eye specialist using actual equipment. This cannot be compared to a computer-based test that is self-administered.

Although online eye tests are sometimes promoted as a convenient way to save time and money, this is rarely the case. An eye exam is a medical process that calls for expertise, accuracy, and the right tools. Anything less could seriously endanger your eyes and vision.