What exactly are clock hours when it comes to the eyeball in opthamology and how is it used for measuring things like different melasmas of the eye?

Question

I was viewing a lecture on opthamology online and they mentioned eye clock hours in the context of certain eye lesions having more or less clock hours than others. It left me very confused.

In: 3

Answer 1

“Clock hours” in ophthalmology are used as a way of orienting what you are talking about in the eye. Think about how a fighter pilot might say something like “On your 6 o’clock!” to refer to something directly behind the person they are addressing. Imagine overlaying an analogue clock face on the eye and consider the hours to be directions.

I suspect that if they are referring to certain lesions as having more or fewer “clock hours” they are referring to the amount of area covered by the lesion.