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2/20/2010

The Eyes are a Window to the Soul

Posted by JoeyBreak

A few days ago I had an appointment for a laser eye exam. It was one of those liability things for the school in which I have proof for the condition of my eyes before I start messing around with the lasers in the lab but I digress. During that appointment the eyes are dilated for the doctor to take a look inside while you stare at the tip of his ear. Below on the left is a picture of what my right eye looked like when it was dilated, about one hour after the appointment. Beside it is a picture of the same eye (under normal operation) a few days later:


right eye dilatedright eye normal

The day the latter picture was taken, I had just finished an experiment showing that in general, the depth of focus for a lens system increases as the effective aperture diameter decreases. This explains why I couldn't focus on the text in a book when my eyes were dilated because the pupil of our human eye is the effective aperture. It also explains why I had such a hard time getting the iris of my eye in focus for the macro setting on my camera: bigger aperture yields smaller depth of focus.

What do you see?

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