Five-minute memoir: Lindsey Davis on life with her brand new eye

I always think first about the robin. I was digging the vegetable patch in my garden, because I was about to have an operation I was trying to forget. The robin flew down to look for worms – a real Secret Garden moment.

They are so bright, and communicative; I felt cheered, as if the bird somehow understood and came to comfort me.

I had a rare eye condition called keratoconus, 'conical lens'. My right cornea had become increasingly mis-shapen and now required a corneal transplant. A consultant had first described it as "like a car tyre getting a bulge in it" – frankly, a worrying image.

The condition affected my sight; for many years I was a willing guinea pig with a succession of innovative contact lenses, though they were hard to fit. Worst was that too much light could enter, very uncomfortably. The cornea became extremely sensitive to touch; one night my boyfriend was horrified to find me sitting on the edge of the bed, with my poor eye swollen and tears streaming as they had been doing for three hours, after his thumb inadvertently brushed my eyelid in his sleep.

The time had come. Even so, when my consultant put me on the transplant list, it came as such a surprise I asked hardly any questions. Would it hurt? How would I feel? What if it went wrong?

A corneal graft is 'major surgery', even though I was perfectly well in myself and the operation involved only a quarter of an inch of tissue. But this is organ donation. The surgery requires a full anaesthetic, so you don't move. That would be easy: the thought of having the front of your eye sliced off is alarming. As a keen dressmaker, I could imagine the skill needed to sew in the tiny new lens.

My friends and family were agitated; I said I would go to the hospital myself, then they could visit afterwards. (I need to explain: there was no question I would be blind. Unlike most people with keratoconus, I am very lucky and have a perfectly good left eye.)

But of course I was stressed. I had been warned I must do nothing strenuously physical until the new lens took – which was why I dug the veg patch like a lonely stalwart beforehand.

When I turned up at the hospital to be settled in, the robin had given me courage. I know that night I read Peter Wiseman's book on the death of the Roman Emperor Caligula, and I do recommend a mad tyrant's assassination, to calm you down in a crisis.

I thought keenly about the person who donated my new cornea – and I had a particular reason to think about their family. I never knew who they were. TV dramas get this wrong: you are discouraged from asking, or making contact – even to say thank you.

But I knew what they had gone through. Twenty years before this, my brother committed suicide. Max carried a donor card. Because there had to be a post mortem, his major organs could not be donated, only his eyes. I know how hard it is during sudden bereavement in terrible circumstances to say you want to do this. That's why I am a very strong supporter of opting out, not opting in.

I have heard people say, they could donate any organ except the eyes, because "they are the window of the soul". That makes me angry. A window is just a pane of glass. It has no effect on what happens either outside or in. A cornea is just the same.

That evening, as the ward grew quiet, a motorbike courier arrived. Being close to the nurses' station I overheard his cheery cry: "Where do you want the eye?" "Oh put it in the fridge!" It could have been macabre, yet the sheer matter-of-factness made me laugh and feel reassured. I'm laughing now, as I remember.

When I came round after the operation, my dear boyfriend was there. He helped me out of the hospital gown and I remember that getting into my own nightie seemed to mark the return to ordinary life. My editor and agent both visited. I remember my editor's amazement to find me wearing an eye-patch yet sitting up reading the paper. My agent had brought wine, but no bottle-opener; we destroyed the cork with a nail file eventually.

At no time did I feel I had acquired part of some other person. When the patch came off, that eye was mine already. Even with the invisible stitch still in, I could see more than the coloured blurs that had been all I could manage for years.

Two decades later, I remember the robin, the courier, the people who loved me, and my unknown donor. We are bonded through this stranger's generosity; they will always be part of me.

Lindsey Davis is the author of 'Master and God' (Hodder & Stoughton). She is also the current chair of the Society of Authors