An eye test reveals much more about your health than just the state of your vision. Many websites today give you the option of testing online for nearsightedness, distance vision and even for age-related macular degeneration. However, an online eye vision test does not replace going for regular eye tests at an optometrist. It is very important to have your eyes tested at least every two years by an optometrist, particularly as you grow older.
When my children noticed that my head was practically hitting my computer screen in my attempts to see, they urged me to go and have an eye test. I realized that it had been about five years since my previous test. Lack of time and the cost of an appointment are just some factors that prevent people from getting regular check-ups. Online eye tests are convenient and may be free but they do not replace comprehensive, in-person eye tests.
What does free vision testing online offer?
Online sites that offer free vision testing are convenient tools for getting some idea of the state of your vision.
A company called Opternative makes the claim that their online tests are as accurate as an in-person refractive eye exam. The eye exam is free and all you need is a smartphone and a computer to take it. You answer a series of questions using your smartphone as a remote control. The test results are sent to a licensed ophthalmologist who writes a prescription that can be filled anywhere.
The problem with online tests is that they are not complete eye exams. They do not currently identify eye health issues or underlying health conditions. These are often only uncovered during a comprehensive, in-person eye exam. Optometrists use a wide variety of tests and procedures when they examine your eyes, ranging from simple ones like reading an eye chart, to more complex ones like using high-powered lenses to see inside your eyes.
What to expect from a comprehensive eye test
The optometrist sat me down and began asking me whether I was having any eye problems, what medication I was taking and the state of my health. She also asked what type of work I did and about eye conditions experienced by family members.
When I had to read the letters on the chart, I found that I could not read the smallest letters on the bottom row. I was seated upright with my chin on a bar and I remembered the funny goggles previous visits. A series of lens choices was placed in front of my eyes and I was asked which of the two lenses in each choice looked clearer. This is always the worst part of the test for me as I often find it difficult to choose between the two options. I hesitate, stammer, say ‘can you show me again please?’ and finally come up with some sort of answer. These tests determine the lens power you need to compensate for any refractive error and so if you want your prescription to be accurate, your answers need to be accurate too. Fortunately, she continues showing me options until I finally seem to be giving the right answers.
Nearsightedness is usually caused by elongation of the eyeball. Light coming into the eye is not focused properly on the retina, making it difficult to see far away objects. Farsightedness is the opposite and is caused by shortening of the eyeball. Astigmatism is an imperfection of the cornea that prevents part of it from focusing light onto the retina. The conclusion was that my vision had deteriorated slightly but not significantly.
She performed various tests such as one where I had to hold my head still and follow the movement of a light with just my eyes. I gathered that she was testing how well my eyes moved and worked together.
When she did the ‘puff of air’ test, blowing air is blown into each eye, I could hardly feel it. This test is used to determine intra-ocular pressure. If the pressure within the eyeball is too high, it can cause damage to the optic nerve. The pressure is a result of fluid not being able to drain normally. It is extremely important to detect this condition as early as possible because prolonged pressure can cause vision loss and blindness. In most types of glaucoma, nerve damage occurs slowly and causes blind spots in peripheral vision. As the disease progresses, tunnel vision and eventually blindness occurs.
The one bit of bad news the optometrist gave me was that I had the beginnings of cataracts. She said I must have more regular eye tests and that they would keep an eye on their growth. Cataracts can cause cloudy patches in the lens that affect your vision. You may see blurry images and be affected by glare from ambient light. Cataract surgery is a a fairly common operation for people over 65.
Other health problems an optometrist can detect
I was taken to another room and I saw what looked rather like a large version of the microscopes we used in the science lab. Once again I was seated in an upright position with my chin resting on a support bar while the optometrist examined my eyes. Then she projected an image of my eye onto a screen. We looked at this image, and she explained exactly what we were seeing. This was the most fascinating part of the examination for me as I was able to see all the different parts of my eye, including the blood vessels and the macula.
I was particularly concerned about macular degeneration as this is the leading cause of a loss of vision in people over 50. My father was beginning to lose his sight at the age of 76 when he passed away and my mother of 82 has recently been diagnosed. Fortunately my macula, the central area of my retina, showed no signs of degeneration. Macular degeneration is diagnosed as either dry (non-neovascular) or wet (neovascular). The dry kind is an early, more common stage of the disease and may result from the aging and thinning of the tissue, depositing of pigment in the macula or a combination of the two processes. The wet kind refers to growth of new blood vessels in an area, such as the macula, where they are not supposed to be.
High blood pressure
The optometrist also told me that the blood vessels in my eye were in good shape. If your blood pressure is consistently elevated (above 140/90mmHg), this creates high pressure in all your blood vessels, even those in your eye. She said that if this was the case, my blood vessels would appear swollen and dark, rather like copper fibers. Consistent pressure in the vessels may eventually lead to hemorrhages in the eyes and damage to the nerve cells. This is why it is so important to keep your blood pressure under control. High blood pressure and diabetes are also major causes of white cotton-like spots on the retina.
Diabetes and high blood glucose
When blood glucose levels are consistently high, multiple small blood vessels form in the retina. Haemorrhages from these fine blood vessels result in damage to the eyes. This is known as diabetic retinopathy and it eventually leads to blindness. Diabetics who do not have strict control over their glucose levels are at risk.
The value of early diagnosis
Many eye problems have no obvious symptoms so you may have no idea that you have a problem. Often times these conditions are treatable, reversible or perhaps controllable if detected early during the disease process. Early diagnosis may just save your sight. Glaucoma, for example, if detected early, can be successfully controlled, provided the patient is compliant with using their medication and goes for regular monitoring and follow-up care.
The optometrist told me that if she had noticed any serious problems, she would have referred me to an opthalmologist. The opthalmologist would then formulate a plan of treatment. If necessary a specialist physician would be seen to treat elevated blood pressure, cholesterol or diabetes to lower risk of heart disease and blindness.
It pays to have a complete eye examination regularly. I was extremely fortunate that no serious problems had developed due to my neglect. Doing a few online eye exams is not enough when you have the possibility of detecting serious health problems by undergoing a a regular, thorough examination.
Here are some products that may help those suffering from age-related eye problems.