Alex (L) and Merlin (R) are Two Boys on a Bike for Sight! In early October they will be cycling 10,000km from Cairo to Cape Town to distribute an innovative new medical device designed by the University of St Andrews to prevent eye disease.

Many great adventures have unexpected beginnings. The bicycle below, made for two, had been given to Alex by some friends as a quirky birthday present. It had never been intended to leave the small streets of St Andrews.

But in the midst of an unbearable heatwave, we soon found ourselves climbing through the Spanish Pyrenees. Well, until the chain flopped off once again, and we collapsed into a roadside flood drain, broke a dry muesli bar in half and pondered our decision to ride through the country on a bike laden with climbing gear.

Alex and Merlin’s original tandem “Roxanne”, laden with rock-climbing gear in Spain.

One year on, and buoyed by that experience, we are making preparations to cover twelve times the distance, through higher temperatures, on a more heavily laden bike. And there might not even be muesli bars…

Albert Einstein said that he came up with some of his greatest ideas whilst pedalling. We returned to the University of St Andrews, had a wash, and then had a think. It was during a lecture that Merlin heard of the burden of eye disease in low-income countries: 240 million people are visually impaired worldwide, equivalent to the combined populations of the UK, Germany, France and Spain. While a staggering 80% of blindness is preventable, health workers in low-resource regions often lack the tools to diagnose and treat the conditions that lead to blindness.

Merlin also learned of a potential solution – the Arclight – an innovative device that can help health workers diagnose eye and ear diseases. At 1% of the cost of traditional tools, this lightweight and easy-to-use device is solar-powered and has been developed by the University of St Andrews specifically to meet the needs of low-resource settings. The International Agency for the Prevention of Blindness advocates it as a key tool in the fight against preventable blindness and would like to see it implemented across the globe. The next challenge faced by Arclight is how to get this new technology into some of the most medically deprived regions in the world.

The Arclight

As we discovered in Spain, a tandem is quite the packhorse and an inexpensive and interesting way of covering large distances – so we approached the University with a proposal. With their support we could carry out the most extensive distribution of Arclights to date. There was, however, just one condition: we had to do it by tandem!

The expedition – Two Boys on a Bike for Sight: Cycling 10,000km from Cairo to Cape Town – will take us through 11 countries, passing through some of the most medically deprived parts of the world where there is also the greatest burden of eye disease. We aim to distribute over 2000 Arclights to health workers free of charge and provide them with the training that is needed to use the device effectively.

Our legs and wheels will take us on a transect of the African continent, through 64 degrees of latitude. Initially, the Nile will guide us through the sandstorms and heat of the Sahara and onto to the 3000m passes of the Ethiopian Highlands. On some nights we will camp under the stars, opening our tent to sunrise over the Serengeti, while others will be spent amongst the noise of Africa’s largest cities.

The majestic Serengeti…

Early preparations began by reading about Scottish cyclist Mark Beaumont’s record-breaking cycle from Cairo to Cape Town. Mark has since become a valuable source of advice on all things cycling and is part of a network of support that includes the University of St Andrews, the Scientific Exploration Society, the International Agency for the Prevention of Blindness and, of course, the RSGS and their Explorers-in-Residence, Luke and Hazel Robertson.

We leap into the saddles in early October. Looking at our maps it seems to be downhill most of the way!

You can follow Alex and Merlin on their adventure and the Arclight project, at, as well as on Facebook, Twitter and Instagram.