smartphone apps for low vision

February is Low Vision Awareness Month. Low vision is a term used to describe significant, permanent visual impairment that cannot be fully corrected with regular glasses, contact lenses, or surgery. This can be due to eye diseases (like macular degeneration), injury, or genetic conditions. Most people with low vision are not totally blind, but have enough vision loss to interfere with daily activities. The goal of low vision rehabilitation is to help people make the most of their remaining vision. It's important to start the process early so that patients can make adjustments and adapt to a new way of doing things.

Fortunately, there are devices that can help people with low vision function more efficiently and independently. There are many types of magnifiers, telescopes, and electronic devices that low vision specialists can help set you up with. This post will focus more narrowly on smartphone applications that can help those with low vision. Big thanks to Omar Mohiuddin, occupational therapist at Duke, for allowing me to use some of his content.

First off, here is an app that simulates low vision conditions: ViaOpta Simulator (Android and Apple). It shows how various eye disease like macular degeneration, glaucoma, etc, effect your vision.

ViaOpta Simulator

Secondly, every smartphone has basic accessibility features that can help individuals with visual impairments immensely. Those features include larger text, voiceover, increased contrast, and much more.

Accessibility features on Apple iPhone

Now for the low vision aids...

If you could only use one app, I would recommend Seeing AI (Apple). It has many of the features we'll discuss below, so it's a handy and convenient tool. Seeing AI can read websites and documents aloud as well as identify products via their barcode. You can teach the app to recognize people, and it can tell you when they appear in the camera frame. More details on this app here.

Seeing AI can identify products using their barcode

1. Magnifiers: There are a ton of these apps out there, and they're used by sighted and visually-impaired individuals alike. Many of them not only magnify text, but invert colors and change the contrast to make reading easier.

• Pocket Zoomer (Android)
• Smart Magnifier (Android)
• SuperVision+ (Apple and Android) and SuperVision mini (Apple and Android)
• Brighter and Bigger (Apple and Android)

Brighter and Bigger allows you to magnify text, invert colors, and adjust contrast

2. Color Identification: These apps use the smartphone's camera to identify the color of objects in view.

• Color ID (Apple and Android)
• Aipoly Vision (Apple) - My two cents here: This app is good for identifying colors, but not that great at identifying objects. I tried to identify a spatula, and the app said it was either a toothbrush or a maraca...

Aipoly can identify colors

3. Object Recognition: These apps use either the smartphone camera or remote sighted individuals to help identify objects.

• TapTapSee (Apple and Android)- My two cents: I found this app to be fairly accurate and specific. You simply take a picture with your smartphone, and the app identifies the object(s) within the frame, using the Voiceover feature to communicate the findings. 

TapTapSee identifies objects

• VizWiz (Android) and Be My Eyes (Apple and Android)- Both of these apps utilize sighted people remotely to help users. 
• Seeing AI (Apple)- As discussed at the beginning of the post.

4. Currency Identification: These apps use the camera on your smartphone and audibly tell you what denomination the bill is.

• NantMobile Money Reader (Apple)
• Money Reader (Android)
• EyeNote (Apple)

EyeNote can identify bills

5. Speech-to-Text: Lots of these exist.

• Dragon Anywhere (Apple and Android, $)
• Speech to Text (Android)

6. Text-to-Speech:

• KNFB reader (Apple and Android, $)- Allows you to take a photo of text, giving you pointers on how to position the camera in relation to the document, and then reads the text aloud.
• Natural Reader Text to Speech HD (Apple and Android, $)- Allows you to listen to webpages, files from your phone, etc.  
• Text Grabber + Translator (Apple and Android, $)- Digitizes printed text.
• Seeing AI (Apple)

7. Reading:

• GoRead (Android)
• Read2Go (Apple, $)
• Audible (Apple and Android, $)- Sighted and visually impaired persons alike love Audible because there are a TON of audio books available. 

8. Navigation: These apps use GPS to help visually impaired persons know their location, their environment/surroundings, and their position relative to other locations.

• Ariadne GPS (Apple, $)- Here's a video of the app in action.   
• BlindSquare (Apple, $)
• ViaOpta Nav (Apple and Android)

ViaOpta Nav can tell you your location, including the nearest junctions and
their position relative to you

If you or a loved one has a visual impairment, talk to your optometrist or ophthalmologist about your options! If they are not able to equip you with low vision rehabilitation services themselves, they can certainly refer you to a low vision specialist that can.

To find a low vision specialist:

• IALVS
• AAO (select "Low Vision Section")
• WhatIsLowVision.org

To find services for the visually impaired: American Foundation for the Blind


CliffsNotes: Visually impaired persons can benefit greatly from learning to use smartphone apps early on.  Seeing AI is a great one to start with!


Additional Resources:

• Living Well with Low Vision
• Hadley Institute for the Blind and Visually Impaired
• AppleVis.com (Apple)
• Eyes-Free Project (Android)

age-related macular degeneration

Fundus cupcake sprinkled with drusen

February is Age-related Macular Degeneration (AMD) Awareness Month. AMD is one of the leading causes of irreversible vision loss among Americans over 60 (1). 

Let's preface our AMD discussion with a quick anatomy review. The tissue that lines the back of the eye is called the retina. The retina has millions of light-sensing cells called photoreceptors (rods and cones). These cells absorb light and convert it into signals that are sent to the brain via the optic nerve, allowing us to see the world around us. The macula is a small area near the center of the retina that is responsible for our central, sharpest vision. Within the macula is a high density of cones, the photoreceptors responsible for color vision. When you look at retinal photos (or the cupcake above), the macula is the dark red area. For reference, here is a labeled photo of a healthy retina.

What is age-related macular degeneration?
Age-related macular degeneration, commonly called AMD or ARMD, involves a breakdown of the tissue that makes up the macula. Waste products called drusen accumulate beneath the retina, in and around the macula. Drusen are the yellow-ish deposits you see in the photo below. This disruption causes the photoreceptor cells to die, which impairs vision. Over time, central vision becomes blurry and distorted. AMD can be classified as either dry or wet.  

• Dry (non-exudative) AMD: This is the most common form of the disease. The early and intermediate stages of dry AMD involve drusen and/or pigmentary changes in the retinal pigment epithelium (RPE). The late stage involves the death of large areas of retinal tissue, called geographic atrophy, which affects central vision significantly.

Fundus photo of dry AMD

• Wet (exudative) AMD: About 10% of dry AMD cases progress to the wet form, meaning that neovascularization has occurred. Neovascularization is the formation of new, abnormal blood vessels under and into the retina. These vessels are weak and can leak, causing vision loss. Neovascularization is bad news bears and warrants prompt treatment (discussed below). Wet AMD typically affects vision more rapidly and more significantly than dry AMD.

What are the risk factors?
AMD is a multifactorial disease. The exact cause is unknown, but research suggests some factors increase the risk of AMD:

• Age. Age is a major risk factor, with most cases typically occurring after the age of 50. 
• Smoking. Several studies have found a positive association between smoking and the development of AMD. The risk of developing the disease for current smokers is at least two to three times greater than the risk for non-smokers (2, 3). Smoking is the leading modifiable risk factor for AMD.
• Family history/genetics. Having a close relative with AMD increases the risk of developing the disease (4). Researchers have identified variants of a few complement genes that are associated with an increased risk of developing AMD (5).
• Diet. Those with diets low in omega-3 fatty acids and antioxidants may be at greater risk of progression to advanced disease (6).
• Hypertension. Some studies have shown wet AMD to be associated with moderate to severe hypertension (7, 8).
• Obesity. Research has suggested an association between body mass index (BMI) outside the normal range and early AMD (9)  as well as progression to advanced AMD (10).
• High cholesterol. Elevated high-density lipoprotein (HDL) levels may be associated with higher risk of AMD (11).
• Sun exposure.  Exposure to large amounts of visible and blue light may play a factor in disease progression (12, 13, 14). 
• Ethnicity. AMD is more prevalent in Caucasians. 
• Gender. AMD is more prevalent in females.

How is AMD diagnosed?

AMD is diagnosed during a dilated eye exam. It may manifest itself in changes in central vision, but it most likely will not in the early stages. Upon dilation, pigmentary changes and/or drusen may be noted by your eye doctor in/around the macula. 

How it is monitored and treated?

• Various tools exist to help monitor AMD and guide treatment: 
• Retinal photo. Periodic photos allow for monitoring progression over time. 
• Amsler grid. This is an easy way for patients to monitor for changes in their central vision. AMD can cause parts of the grid to appear distorted or missing. I suggest that my AMD patients leave it on their refrigerator and test each eye a few times a week, monitoring for any changes. 
• The ForeseeHome monitoring device utilizes a similar concept. Patients are presented with a series of straight lines containing a wave/bump, and the patient must identify where the distortion is. The device collects the data and alerts the patient's eye doctor if there are abnormal results. 
• Optical Coherence Tomography (OCT).  A scanning laser is used to image the tissue of the back of the eye. It can produce a cross section of the macula, showing retinal thinning or thickening.  

OCT showing drusen (red arrows) below the retina

• Fluorescein angiography (FA). Fluorescein dye is injected into a vein in the arm and photos of the retina are taken as the dye reaches the retinal vessels. An FA may be ordered to identify neovascular membranes, evaluate leakage, and/or guide treatment. 
• Coming down the pike: OCT Angiography. This technology just got FDA approval in the US. It will allow doctors to image the vessels of the retina and choroid without injecting a contrast dye (unlike an FA). 
• Treatment: 
• Dry- There is no FDA-approved treatment for dry AMD as of yet. Plenty of research is being done in this area. Studies have shown that antioxidant supplementation may help slow progression to advanced AMD (15, 16). For more information on ocular nutrition, check out this post.  
• Wet- Most cases of wet AMD are treated with anti-vascular endothelial growth factor (VEGF) drugs. Anti-VEGF drugs are periodically injected into the eye to stop abnormal vessel growth. Photodynamic therapy (PDT) and laser photocoagulation are also treatment options, though less commonly used.

Vision loss is often life-altering and difficult to cope with. There are support groups and low-vision rehabilitation resources available to those dealing with AMD. Low vision aids include hand-held, stand, or spectacle magnifiers, video magnifiers (CCTVs), and even implantable telescopes! We'll do a separate post on low vision devices and rehab services later on, but here's a great place to begin: Living Well with Low Vision.

CliffsNotes: AMD is a multifactorial disease with several modifiable and non-modifiable risk factors. The best way to prevent vision loss from AMD is to have routine dilated eye exams, especially if you fall into a higher-risk category.   


Additional resources:

• All About Vision: AMD
• NEI: AMD Facts
• Get Eye Smart: ARMD
• Foundation Fighting Blindness
• Prevent Blindness

Essential Eye Nutrients

Food and lifestyle choices can influence your eye health and may help to reduce the risk of some age-related eye diseases.  Check out this quick summary of the nutrients essential for good eye health.
*Disclaimer: I am not a nutritionist or a dietician.

• Zinc (red meat, poultry, oysters, beans, fortified cereal)
• The Food and Nutrition Board recommends: 11 mg/day for males, 8 mg/day for females
• Zinc is an essential mineral that is involved in cell metabolism.  It is highly concentrated in the retina and choroid of the eye.
• Vitamin E (nuts, seeds, vegetable oils)
• The Food and Nutrition Board recommends: 15 mg or 22.4 IU/day for both males and females
• Vitamin E is a powerful antioxidant that is involved in immune function.
• Vitamin C (citrus, strawberries, broccoli, red and green pepper, kiwi)
• The Food and Nutrition Board recommends: 90 mg/day for males, 75 mg/day for females
• Vitamin C is an antioxidant that helps absorb UV radiation. It is found in high concentrations in the lens, aqueous humor, and vitreous humor of the eye.  On a long term basis, increased intake of vitamin C (alone or in combination with other antioxidants) has been shown in some studies to reduce the risk of developing nuclear sclerotic cataracts (1, 2).

The National Eye Institute's Age-Related Eye Disease Study (AREDS) found that daily intake of 80 mg zinc, 2 mg copper, 500 mg vitamin C, 15 mg beta carotene, and 400 IU vitamin E could reduce the risk of progression to advanced Age-related Macular Degeneration (AMD) by about 25% and visual acuity loss by 19% in individuals at high risk for the disease (3).  Since that study, researchers have found that substituting beta carotene with 10 mg lutein and 2 mg zeaxanthin is safer and more effective (4).

• Vitamin A (beef liver, carrot, pumpkin, sweet potato)
• The Food and Nutrition Board recommends: 900 micrograms or 3000 IU/day for males, 700 micrograms or 2300 IU/day for females
• Vitamin A is essential in the proper functioning of the retina, as well as the conjunctival membrane and cornea.  Most Americans get sufficient vitamin A from their diet, but vitamin A deficiency (VAD) is actually the leading cause of preventable blindness in children world-wide (5).
• Lutein (kale, spinach, collards, egg yolks) & Zeaxanthin (gogi berries, orange peppers, corn)
• The American Optometric Association recommends: 10mg/day of lutein and 2mg/day of zeaxanthin
• Lutein and zeaxanthin are carotenoids that are abundant in the macula of the eye as well as the lens. They are antioxidants that help lower your risk for Age-related Macular Degeneration (AMD) and cataracts.

From Review of Optometry

A follow-up to AREDS- AREDS 2- found that people with the lowest dietary levels of lutein and zeaxanthin who added supplements of the two had a 26% reduced risk of developing advanced AMD.  Those with the lowest dietary intake of lutein and zeaxanthin also saw a 32% risk reduction in progression to cataract surgery with the introduction of these nutrients (6).  Most Americans only get 1-2 mg of lutein and zeaxanthin combined on a daily basis through their diet, so many of us fall into this category.

Fun Facts: Vitamins A, D, E, and K, as well as lutein and zeaxanthin, are fat-soluble.  A small amount of dietary fat (ie: olive oil, avocado, nuts, seeds) can help maximize the body's absorption of these nutrients.  Cooking (steaming, sautéing, or puréeing) leafy greens actually allows more access to the important nutrients by breaking down plant cell walls.

• Omega-3 Fatty Acids (wild salmon, mackerel, tuna, sardines)
• The American Heart Association recommends eating at least two servings of fish (especially oily fish)/week
• The 3 types of omega-3 fatty acids the body uses are ALA, DHA, and EPA.  DHA and EPA have structural and protective functions in the retina, and they also have anti-inflammatory properties.  Beyond the cardiovascular health benefits, diets rich in DHA and EPA have been linked to a significant improvement in dry eye symptoms (8, 9). 

Eye vitamins and other supplements can help you meet your recommended daily intake of these nutrients. Be sure to discuss this with your optometrist or ophthalmologist.  I also recommend communicating with your primary care doctor before beginning any supplementation regimen- it's important to give your PCP the full picture of what you do to manage your health.

If you want to find an optometrist that specializes in ocular nutrition, look here.

CliffsNotes: What you eat can influence your eye health and may help to reduce the risk of age-related eye diseases.  

Additional Recommended Resources:

• AOA: Diet and Nutrition
• All About Vision: Nutrition
• Get EyeSmart: Diet and Nutrition
• Eyefoods: A Food Plan For Healthy Eyes
• Visionary Kitchen: A Cookbook For Eye Health