We use the term low vision but for many people that term can be confusing, because what does that mean exactly? Low Vision really encompasses a number of findings and a number of symptoms for the patient. So if a patient has conditions such as macular degeneration, glaucoma, diabetic retinopathy, or any other disease process, then it can lead to the patient having low vision. One of the main things we're gonna see in a patient with low vision is reduced visual acuity. So this means that typically, we want to correct a patient to 20/20 on the eye chart. Once a patient has physical damage to the eye from the disease process, they're no longer correctable to 20/20. So as time goes on, particularly if it's a progressive condition, then we may see the visual acuity reduced to 2040. And then in a few years, it may be reduced to 20/70, and so on.
The effects of reduced vision acuity is going to be difficulty in doing things like driving, difficulty in watching television, seeing detail on faces, recognizing people when you're in places, and having difficulty with things up close. Most low vision patients who have reduced visual acuity will have trouble reading, using a computer, using a phone, or doing any detailed near vision as well (such as sewing or playing cards).
Another big thing that we see as a symptom of low vision is going to be what's called reduced contrast sensitivity. So when that decreases, that means that if everything's like really nice dark black on a white background, it's going to be easier for the patient to see. But as it starts to fade out, it becomes more difficult. So if somebody is trying to read something on a paper and it's black ink on a white background, they may be able to see it in a certain size. But when they pick up the newspaper, they may no longer be able to read that because the contrast is poor.
Another common finding in low vision patients is glare sensitivity. This could be where they're sensitive to lighting indoors or outdoors or both. And so we may find that these patients tend to do things like wear a hat, or sunglasses frequently. It can also be a disability glare to where it washes things out and they're no longer able to see, the best example to compare that to is if you've ever been in a really dim setting, like say, at a movie theater and you've been in the dark for a long time and then you emerge into the bright sunlight and it's blinding for a moment and you're unable to see. That's what somebody with low vision can experience on a regular basis.
A low vision optometrist will assess the cause of vision loss and guide the patient on the best adaptive tools and methods that can help them function with the vision that they have. For example if the low vision exam shows that the primary cause of low vision is reduced visual acuity then there are specific devices and adaptations that can help that patient regain their visual independence. Examples include magnification, bioptic telescopes for driving, prisms, and telescopes. If the patient's low vision is a result of contrast sensitivity or glare then filters or digital magnifiers may be recommended. Since many patients may have multiple causes of visual impairment it is important to schedule a low vision exam so that our doctor can give you more specific information as it relates to maximizing your remaining vision.
Learn more about the symptoms of low vision here.
To schedule a low vision exam call our office at (423) 710 3965.