Posted on January 21, 2018
There are a lot of online eye tests available, which allow you to check your eyes free of cost, sitting in the comfort of your home. As life is becoming increasingly simplified with apps for almost everything we know making our life easier, people have been lead to believe that an online eye test may actually be a substitute for a time consuming visit to the doctor or optometrist. This article will discuss with you the pros and cons of an online eye test.
What Does An Online Eye Test Tell You?
The online testing is a very basic, and crude assumption of your vision for near and distance. All online tests come with caveats in small print. They are merely designed to give you an idea of how good or bad your eyesight is, and can only direct you to seek help from your eye doctor.
Some online eye tests are equipped to provide you with a prescription for glasses and/ or contact lenses, but in real life, these are not as efficient as a visit to an optometrist. Some may check your contrast sensitivity and color vision also. That is the maximum these tests offer, they do not check eye pressures, or evaluate the front (anterior segment) or back of the eye (retina and optic nerve), all of which are an essential part of a general eye check.
These tests, most emphatically, are NOT a substitute for a proper and comprehensive eye examination which must be carried out by your eye care professional, at least every two years, unless you have been advised otherwise.
What Is The Biggest Pit Fall Of An Online Eye Test:
If an online eye test tells you that you have poor vision, you will seek medical help. In case you did have a problem, you will find a solution to it with your doctor. This is the perfect scenario. In case you do not have a problem and were misdiagnosed by the online eye test, you would have only suffered from anxiety (if at all) till your doctor examined you and reassured you that your eyes are perfect.
The problem arises when the online test gives you an all clear, in the presence of an eye disease, a situation which is called a false negative, and can have grave clinical implications. Several serious eye diseases, like glaucoma, diabetic retinopathy, retinal holes to name a few, do not have any visual symptoms initially. That is, a cursory test of vision alone cannot pick up these diseases, which are all potentially sight threatening.
In fact, a false negative online test result can mean you will be lulled into a false sense of security, believing that you do not need to see your doctor since your test was “perfect”.
What Constitutes A General Eye Examination?
The general eye examination is a lot more than just checking your vision for near and distance. It usually comprises of two sections, in the Indian scenario. Most doctors and clinics have a two-step approach to a general eye evaluation. The first step is carried out in the optometrist’s chamber and comprises the following:
- Brief discussion regarding history of your eye health, and general health, any specific concerns
- Evaluation of uncorrected vision for distance and near
- Evaluation of refractive eye and power of glasses/ contact lenses
- Evaluation of best corrected vision, and prescription of glasses/ contact lenses
- Evaluation of alignment of your eyes, and of eye muscles
- Measuring of eye pressure, or intraocular pressure
The second step is carried out by the doctor himself/ herself. This is the backbone of the eye examination and consists of the following steps:
- Detailed discussion about your eye and general health. The doctor will also discuss your concerns regarding your vision correction and symptoms in greater detail.
- Slit lamp evaluation of the anterior segment of the eye which involves a complete check-up of the eye including the lids, conjunctiva, cornea and iris.
- 90 D/ 66 D evaluation which is also carried out on the slit lamp, using a magnifying lens to evaluate the health of your central retina and the optic nerve, which connects the eye to the brain.
- Dilated evaluation involves instilling eye drops to dilate your pupils. This allows a more detailed evaluation of the optic nerve and the periphery of the retina. The doctor may, or may not, order this test each time, based on his/ her clinical discretion.
- The doctor may also repeat any of the tests performed by the optometrist in case of doubt, or sometimes, only for verification.
- Your eye health and specific findings will mean that the doctor may or may not recommend any further tests before arriving at a diagnosis and management plan.
So Are Online Tests Worthless?
Not really. Even though these tests are not a replacement for an eye evaluation, they may sometimes prove to be of value. In case you are feeling a decrease in your vision, an online test that proves that your vision has actually deteriorated, will actually prompt you to seek an appointment with your doctor at the earliest.
Also, in some cases, your doctor may recommend an online vision test to help you monitor your eyesight between routine eye exams.
So it is important to remember that an online test may supplement your eye test with the doctor, but is not a substitute for the same. You will still need the routine eye exams as frequently as your eye doctor recommends. This is because a detailed eye evaluation by a trained ophthalmologist is the only way to know that your eyes are healthy and free from any vision-threatening diseases.