Solar-powered Scope

The Arclight saves sight and sound.

01 July 2017

An estimated 285 million people around the world are visually impaired, and 360 million are hearing impaired. While the majority of these cases are considered preventable or treatable if diagnosed prompt ly, getting that diagnoses can be difficult and expensive for many. A low-cost, solar-powered ophthalmoscope called Arclight aims to solve this issue.

Developed by a team led by University of St Andrews (UK), the pocket-sized Arclight can also be used as an otoscope to look for any problems in the ear that may lead to hearing loss. Since the majority of vision and hearing impairment cases are found in countries with the least access to medical care, Arclight was designed specifically to be an easy-to-use tool for screening programs in low-income countries.

Doctors in poorer countries rarely have ophthalmoscopes, which can be complex, heavy, and expensive. Available tools are often hand-me-downs that don’t work properly because they need hard-to-find or costly parts, such as bulbs and batteries.

“Arclight is the result of years of hard work by a small team of enthusiasts,” says Andrew Blaikie, a clinical academic at St Andrews, who also works as an eye surgeon at Queen Margaret Hospital. “These efforts have brought simple, frugal yet highly effective tools to health care workers who would otherwise be unable to make the early diagnoses needed to prevent needless blindness.”


Uncorrected refractive errors are the main cause of visual impairment, and cataracts are the leading cause of blindness. Arclight lets an examiner see the front and back of the eye, revealing any major blinding conditions such as trachoma, cataracts, glaucoma, or diabetes, and make quick, on-the-spot diagnostic decisions. The adjustable lens slider has three different lenses, allowing for a rough correction of a patient’s refractive error.

The device uses three LED light sources – two white LEDs to render eye and ear tissues accurately and evenly and a unique violet/ blue LED to reveal subtle yet vital corneal defects. Being low in infrared and ultraviolet, the Arclight enables a comfortable and safe examination for the patient.

Weighing less than 1 oz (18 grams), the Arclight can be carried in a shirt pocket or worn around the neck. The compact design features a small, direct ophthalmoscope at one end with an illuminating magnifying loupe and a detachable otoscope at the other end. The otoscope specula are easily attached by push-fitting over the loupe. The integrated solar panel or a USB port can power the built-in, rechargeable battery. Each unit includes a small color vision test, a near visual acuity chart, a ruler, and a gauge for measuring pupil size.

Andrew Blaikie using Arclight on a student.
Courtesy of Arclight Medical

In collaboration with the Fred Hollows Foundation (Australia) and the International Agency for Prevention of Blindness (UK), thousands of Arclights have been distributed to Malawi, Ethiopia, Kenya, Fiji, and other countries.

The device has also proven to be an ideal tool for medical students and doctors in the UK. David Harrison, director of research in the Medical School at St Andrews, says the Arclight shows how universities, health services, industry, and partners outside the UK can work together to meet global needs in a realistic and effective manner.

“We will be providing this versatile and clever instrument to our medical students as they enter clinical training,” Harrison says. Blaikie notes that the team, which includes colleagues from the University of Leicester and University College London, plan to add internal memory to the device, which would be loaded with teaching material and allow image capture by mobile phones.

“At the same time,” he adds, “we are developing several other potentially disruptive low-cost diagnostic tools aimed at serving the needs of health care workers in poorer countries.”

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