Question: How did the machine see to the back of her eye?

Dominique Sleet answered on 3 Jan 2020:

The machine shines a focused laser beam of light through the pupil of the eye. The pupil is basically just a hole in the centre of the coloured iris which is how light normally enters your eye. The machine however then measures and records the light that is reflected back to produce a high resolution image of the back of your eye.