How to Conduct an Eye Exam With Your Smartphone
Although some casual apps are available that claim to allow patients to test their own vision, they pale in significance when compared to the sheer diagnostic power of the modern tools for eye doctors available for smartphones. By allowing rapid, cost-effective diagnosis of eye issues anywhere that a doctor can take a mobile phone, these apps are a major step towards combating blindness.
Peek, the Portable Eye Examination Kit, was developed initially for use in developing countries as a low-cost alternative to traditional testing equipment. It can be used on most smartphones and requires only a copy of the app for a basic eye test. By using a tumbling letter rather than the standard alphabet-based sight charts, it allows patients who speak any language to have the same experience. The person assisting the patient with the test needs no special training, as all that is required is to hold the phone 6 feet away from the patient and swipe it to indicate which way the patient sees the letter as facing. By shaking the phone, the helper can also register that the patient cannot see the letter.
As well as facilitating basic eye exams, Peek offers a physical add-on that substitutes for an ophthalmoscope to capture images of the retina and take information about any issues, such as cataracts or macular degeneration, that might be developing. This is done in the same way as taking a regular photo. The results, along with the information from the patient's basic sight test, can be immediately sent to a qualified diagnostician in any part of the world, allowing remote diagnosis by experts that enables patients to work out how urgently they need to seek treatment.
While Peek offers a chance for users to conduct an eye exam with minimal equipment and without a trained person physically present, mobile phone apps and add-ons offer even more tools to trained professionals. Numerous smartphone patient assessment tools are now available for mobile eye doctors and those working in difficult environments. The Near Eye Tool for Refractive Assessment, or NETRA, developed by MIT, uses a pinhole adapter built in to a simple clip-on eyepiece to measure refractive differences.
There are also a range of apps that allow optometrists to assess visual acuity using modern interactive visual acuity tests for preschool children and those who cannot read English. Some applications also offer tests for color vision, astigmatism and eye movement abnormalities.
While conducting an eye exam is usually an optometrist's privilege, many people in developing countries and rural areas do not have regular access to trained professionals. Going for long periods between eye exams or, worse, not being able to have an eye exam at all, can lead to vision problems and eventual blindness. Now, however, it is possible to use a smartphone to conduct accurate eye exams.