Kari Lane is a doctoral-level registered nurse. Her expertise is in geriatrics. She has a familial, hereditary, sensorineural hearing loss.
What Is Low Vision?
Low vision results from reduced visual acuity (visual acuity is the sharp, detailed central vision that we use to see objects straight-ahead) or impaired visual field (visual field is the peripheral or side vision) that glasses, contact lenses, or surgery cannot correct.
While vision impairment is not widely accepted, vision impairments can range from mild vision loss (partially sighted) to severe vision loss or even total blindness. It is commonly accepted that visual acuity between 20/40 and 20/63 would be considered mild vision impairment, 20/80 to 20/160 would be moderate visual impairment, and 20/200 or worse is regarded as a severe visual impairment. Legal blindness is defined as having a visual acuity of 20/200 or worse (in the better-seeing eye after correction with glasses) or a visual field diameter of 20 degrees or less.
Why Does Low Vision Occur?
Low vision can occur for many reasons as we get older. Typically, as a person with no visual changes nears 40, the eye begins to experience changes due to age. First, the lens starts to get less flexible. This means the lens cannot adjust and change shape as it did previously. This is known as accommodation and means it is more difficult to focus on objects up close, like reading. This condition is called presbyopia. Second, the amount of light that reaches the retina is drastically reduced. Related to this, the pupil size becomes smaller. The lens also absorbs light as the lens becomes cloudier with the formation of cataracts; another common condition due to age. However, we know that cataracts themselves do not necessarily cause low vision.
How Does Age Effect Vision?
As we age, we also have a limited ability to adapt to sudden changes in light (bright light to low light takes longer to adjust to). This change is due to limitations in the pupil's ability to adjust its size, cataracts, and changes in the nerves located in the retina. Finally, changes in both the lens and the cornea make it more difficult to tolerate glare. Everyone has some trouble with glare, but older adults can find it highly distressing and nearly blinding when exposed to glare from even a shiny floor. These changes make vision more complex. However, they typically are not the primary cause of low vision.
Medical Reasons for Low Vision in Older Adults
We will discuss several medical conditions that cause low vision. These conditions will vary in seriousness and severity.
Patients experiencing glaucoma have trouble with their peripheral vision first, which means the edges of their vision become fuzzy first, and as glaucoma worsens, the visual field becomes smaller. Glaucoma is due to increases in intraocular pressure, this increased pressure damages the ocular nerve. Persons with glaucoma will have trouble with walking independently, reading (as glaucoma increases in severity), driving, and being startled because people will suddenly appear in their visual field that they do not expect.
Cataracts gradually become thicker and will eventually require surgery to restore vision. Most people have no symptoms in the early stages, but as cataracts become thicker, vision is impaired more significantly. Patients report high sensitivity to glare, altered color perception, image distortion (see image below), and reduced visual acuity. Lack of treatment makes it difficult for people to drive, understand written text, and move about independently. People who smoke, are older, are diabetic, and use alcohol are at higher risk of cataracts than others.
Diabetic retinopathy is caused by diabetes. When someone has diabetes that affects their retina, the blood vessels in the retina are damaged. This damage causes the blood vessels to leak, grow in different ways, and form scar tissue. Diabetic retinopathy can occur at any age and is the most common cause of blindness in adults. Patients with diabetic retinopathy experience low vision, macular swelling, and blind spots. This means they will have trouble with things that require the center part of their vision, such as reading and recognizing faces. They also report a problem with losing depth perception, so driving and even walking independently are difficult.
Macular degeneration can occur at any age; however, for older adults, it can be severe. Macular degeneration is a disease that progressively worsens over time. The light-sensing cells in the macula (a part of the retina) are damaged. These light-sensing cells are responsible for vision in the center portion of our vision. Macular degeneration is the leading cause of blindness for Caucasian Americans and accounts for 54% of blindness in recent studies. People with macular degeneration will have problems with small details such as reading. They may have problems recognizing faces and have difficulties with vision straight ahead. Driving will be impossible at some point. Patients also commonly describe losing color and contrast differences. Due to loss of depth perception, patients may have trouble walking safely alone.
Tips for Staying Engaged and Independent
Keep it simple when possible. Begin with annual eye exams. The best way to treat many of these vision problems is to catch them early. If more frequent eye exams are needed, your physician will let you know.
At Home Tips for Independence
In the home, you want to maximize independence for the patient. If they live independently, let's keep it that way. Even if they live with someone else, small changes can make a big difference.
- Eliminate tripping hazards. Remove anything that could be a trip hazard. Common trip hazards include throw rugs, clutter, footstools, ottomans, power cords, fans, anything on the floor except the major furniture and appliances.
- Provide contrast between light switches and wall surfaces. It can be challenging to locate when a switch plate is similar in color to the wall surface, and changing to red or another high contrast color will help.
- Avoid flooring with patterns or stripes. Use simple colors for flooring and nothing too busy. When there is a complicated pattern in the flooring, people can become confused or dizzy.
- Window coverings need to be easily adjustable. If possible, consider using a remote control for window coverings. This allows a person to control the window coverings easily from their favorite chair, and this also helps people prevent the light and glare in the room.
- Mark steps and stairways. Actions of any kind need to be marked with some form of visual identification, and this will aid in preventing falls. Add stripes of bright contrasting color on the edges of the steps.
- Install railings and handholds. Handrails and handholds need to be strategically located on stairs, of course, but also by the toilet, the laundry, and other locations where falls are common.
- Use paint for maximum contrast. Every doorframe should be recognizable and contrast with adjacent wall surfaces to allow you to determine whether a door is open or shut quickly, Levine says.
- Ensure the countertops have some high contrast color. When your central vision is impaired, it can be hard to see where the countertop ends if the floor is a similar color. You do not have to change the countertops to do this. You can eliminate this problem by providing contrast between the countertop and flooring or putting a strip of colorful tape or decorative transition material at the edge of your kitchen counters.
- Dishes. Red dishes are highly recommended for people with low vision, and this is a high contrast color and helps people notice the edges of their plates and even silverware is also red color.
- Use under-cabinet task lighting. Installing lights under your kitchen cabinets doesn't have to be expensive, and it can make it a lot easier to see what you're doing.
- Bathroom modifications. Walk-in showers and step-in bathtubs promote independence and eliminate the need to climb over a barrier to bathe. This may be the most expensive part of updating this home. Install grab bars (make sure they are secured to a stud and are sturdy). Using nonslip treads in a high contrasting color will also reduce the risk of falls. Finally, a shower bench is helpful for those that have trouble standing long enough to shower.
- Add lighting to closets. You can install additional lighting in cabinets to make it easier to find items. Easy stick-on lights will be helpful and inexpensive.
- Use handy handheld magnifiers. Keep several on hand, near your medications, the TV remote, and the phone.
- Reading. Use a handheld magnifier, a large print book, or books on tape when vision is poor enough. There are also vision magnifiers that will significantly enlarge the print, and persons may need it as large as 24-point.
- Increase Good Light. Good light for older adults is light that comes from the ceiling and is directed downward. A higher wattage bulb can be helpful. If needed, add additional lights to the ceiling.
- Sew shapes on their clothing. For example, triangles match, so they know they will fit if they locate a triangle on a top and a bottom. You can do this for socks as well if persons are specific about their socks matching.
- Use a scarf. At mealtimes, people with low vision often worry about having food on their clothing after eating, and they likely will not be able to see that food. Using a heavier scarf for the ladies can help catch those spills without being unfashionable. Men, I recommend a lovely large bandana to catch the spills.
Key Points When Helping a Person with Low Vision
When you meet someone with low vision, it is essential to tell them who you are. Saying something like, "Hi, Carol, I'm Simone, your nurse for today." Also, let them know when you are leaving their space. Give them specific verbal directions such as "You can sit in the chair against the white wall about four steps in front of you."
Read directions to them, use color-coding and oversized shapes to help them differentiate from things like times for medications or different medications. When you are done with directions, ask them to repeat those directions back to you so that you know they understood.
Count steps with them. It is 14 steps from your chair to the kitchen counter, and it is eight steps from your bed to the laundry room. Eventually, they will learn how far it is, but it does take some time.
Ovenseri-Ogbomo, G.O., Osafo-Agyei, H., Akpalaba, R.E.U., Addy, James, & Ovenseri, E.O. (2014). Impact of low vision services on the quality of life of low vision patients in Ghana. African Vision and Eye Health, 75(1), a19. http://dx.doi.org/10.4102/aveh.v75i1.19
Baguhn, S. Early intervention orientation and mobility: A Dephi study of the content of birth to 6 orientation and mobility skills inventory (B6OMSI). (2021). Journal of Visual Impairment & Blindness. https://doi.org/10.1177/0145482X211047626
Zapata, M.A. (2021). Mobility tool use relates to disability affirmation among adults with visual impairments. Journal of Visual Impairment & Blindness. https://doi.org/10.1177/0145482X211046684
Lundalv, J. & Thodelius, C. (2021). Risk of injury events in patients with visual impairments: A Swedish survey study among hospital social workers. Journal of Visual Impairment & Blindness. https://doi.org/10.1177/0145482X211046666
This content is for informational purposes only and does not substitute for formal and individualized diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed medical professional. Do not stop or alter your current course of treatment. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
© 2021 Kari Lane