There is a huge unmet need for low vision services. About 1.5 million people in the U.S. have vision worse than 20/60, with another 185,000 reaching this point every year.

Millions more have best-corrected acuity within the 20/40 to 20/60 range, according to Chan and colleagues.

Unfortunately, in many parts of the country, there are very few low vision specialists to meet this need. Part of that, I believe, is because low vision, as it was taught to most of us in optometry school, consists of mathematical formulas for figuring out magnification rather than practical skills for helping patients function better with reduced acuity.

Not only does low vision affect patients’ independence when they can no longer drive, but it can also contribute to falls, depression and social isolation. Patients’ functional acuity may be very different in real life than it appears to be at the autorefractor or when looking at a high contrast eye chart at the phoropter. They may have much worse vision in lower contrast situations and better or worse vision from different viewing angles. Faces, for example, are quite low contrast. A patient with low vision may be embarrassed not to be able to recognize friends and neighbors.

Ideally, I would encourage colleagues to identify and refer to low vision doctors and therapists. But if there are no such specialists in your area, here are five things any practitioner can do to help patients with reduced visual acuity:

Ask about functional goals. Doctors tend to think in terms of improving Snellen acuity and may focus on magnification to improve reading. However, the patient may be most distressed by not being able to see the food on their plate or clip their fingernails. Find out what activities are challenging for them and see if you can identify solutions.

Discuss lighting. I am constantly surprised that people do not realize the impact of task lighting. Overhead ceiling lights that are too far away to help and table lamps with diffusing shades — the most common type of lighting in our older patients’ homes — are insufficient for many visual tasks for those with normal vision, let alone low vision. Suggest bright task lighting, with the light source pointed directly at their visual target. You can also suggest that patients try different color temperatures of LED bulbs, as some will do better with warmer or cooler light.

Try filters. It’s not unusual for a low vision patient to wear sunglasses to cut down on glare, but then trip over a curb because the glasses reduce their own contrast too much. Although a low vision specialist might test a number of filters, you can pretty quickly try just three (yellow/orange, gray and amber or yellow/brown) to see which one improves contrast. For a patient with a retinal disorder, the blue end of the spectrum may be too dazzling, so the yellow/brown lenses, which block more of the blue light part of the spectrum, may be most effective. A very important aspect is that indoor environments such as stores and offices that have “daylight” fixtures will debilitate many low vision patients. In these settings they may need lenses with a different shade or a lighter shade of what they use outdoors.

Perform a directional acuity test. The “central” scotoma in patients with age-related macular degeneration or diabetes is almost never exactly in the center of their field of vision. Using a handheld Feinbloom low vision eye chart, you can quickly determine which portion of the field is most compromised. Other types of charts may be great for measuring visual acuity, but because they are horizontally linear they will not show the scotoma and may well mask it. Demonstrating to your patient is critical for success.

Counsel patients to adjust their viewing angle to see better. For example, if the patient has trouble seeing faces, I suggest they decenter the blind spot by looking at where my top hat would be if I was wearing one (for an upper central field scotoma) or where my bow tie would be (for a lower central field scotoma). A low vision therapist can spend more time training someone to do this, but even making the suggestion can be an “ah-ha!” moment that is very empowering to the patient with low vision. They have previously only been told what they do not have, so early on in the evaluation the patient readily sees what we help them with.

These tactics can dramatically help patients adapt to reduced vision, even when they are 20/40 or 20/50, before they reach the formal definition of “low vision.”

Gary Asano, OD, FAAO, is an expert in low vision rehabilitation and a tireless advocate for patients with low vision. After more than 25 years in private practice, he concurrently was a clinical assistant professor to Southern California College of Optometry (SCCO) and Western University College of Optometry externs and residents. Furthermore, he served on staff as a low vision specialist at Kaiser Permanente for more than 12 years. He has been honored with the SCCO Optometry Distinguished Alumnus award in 2021, the American Optometric Association Vision Rehabilitation Committee-Jerry Davidoff Memorial Low Vision Care Service Award in June 2019 and the Envision Oculus Low Vision Award in August 2018. In 2009, he founded the California Optometric Association’s Low Vision Rehabilitation Section, which continues to be very active and the largest low vision body in the country. Asano will be teaching the course: Low vision rehabilitation – Far more than visual acuity, at the 2022 NORA conference. For more information and to register, visit https://noravisionrehab.org/about-nora/annual-conferences/2022-annual-conference.

Disclaimer: The views and opinions expressed in this blog are those of the authors and do not necessarily reflect the official policy or position of the Neuro-Optometric Rehabilitation Association unless otherwise noted. This blog is for informational purposes only and is not a substitute for the professional medical advice of a physician. NORA does not recommend or endorse any specific tests, physicians, products or procedures. For more on our website and online content, click here.

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