How to Build a Retina

Article by Vanessa Restrepo-Schild 

THE Earth has been populated by tiny chemical factories for over a billion years. These factories are living cells, formed from an aqueous solution of chemicals encapsulated by membranes. The extraordinary machinery of these factories takes in raw materials and processes them into substances that continue to create more life. And life, based on complex reactions in water, has endowed us with remarkable capabilities. Just consider our eyes: looking up at the sky, we can make out the fuzzy patch of light of a constellation, at an inconceivable distance of 2.5m light years.

Just 20 years ago, I asked my parents a question: why is technology so different from us? It made no sense to me how techonology always seemed rudimentary when compared to nature. Twelve years later, I went to university having decided to dedicate my scientific life to making life-like technology. I was full of excitement about all I was going to learn. But, the place I thought would bring me nearest to my dream, was making me feel further and further away from it. Pressing my hands against my face, I refused to memorise yet another phylum, another class or another order during those dreadful, dreadful taxonomy lessons. The beauty and infinite diversity of colours, shapes and forms found throughout species had been stripped away by the alienating classification exercise.

The need to find differences had created a distraction from the fundamental similarities shared by all living things. I felt as if life had been concealed from me, and I was determined to begin a search, a search through a vacant space, which I could fill by using my own imagination.

By putting together carefully-defined aqueous solutions of chemicals, could I replicate the fundamental mechanisms of cells and construct my own forms of life? But with billions of molecules inside of each cell, the task had to be reduced to choosing just one function and finding out the minimal components to make it happen.

Choosing a function to explore was easy. I decided to replicate one of the senses: touch, smell, hearing or vision. Of these, vision offered by far the best molecular understanding. All the crucial molecules had been isolated and the mechanism was well known. That was a relief, as the eye has taken humans further than any other sense. It has allowed us to discover the depths of our oceans, the immensity of our mountain ranges and the infinity beyond our sky.

Now, this was all in my head. It seemed straightforward. I felt as if I could do it in a week and my original frustration from sitting in one too many lectures would be over with. In reality, it took two years of intensive work, a limited personal life and a result that, although successful, was nowhere near my original imagination. 

Article by Vanessa Restrepo-Schild 

PhD candidate, University of Oxford

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