Thank you OrbitSurg but I am still confused! I know to look at superior retina you look in inferior mirror and that left-right orientation is still same (too see lesion at 6 oclock look in 12 oclock mirreur; to see lesion at 11oclock look in 7 oclock mirreur). But what about nasal-temporal? If you want to see real lesion at 3oclock you look in 9oclock mirror no? If you want to see lesion in 8oclock mirror where do you look at - the 2 oclock mirror or 4 oclock mirror? This is very stressing to me and is nowhere in any textbooks.
Some of the gonioscopy textbooks will show you this orientation, and there can be questions on boards and OKAPS about his exact topic.
If you want to go easy on yourself early on, the only consider the center of the mirror, and think of it as one clockhour at a time. That eliminates the orientation part of the question, and you can concentrate on finding what you need to find. The center of the mirror will see directly across the "clock", so yes, look at 3 to see something at 9. Look at 2 to see something at 8, etc.
Now, with the wider view lenses, you can see about 3 clock hours at a time. This is where the confusion usually comes in. If you have the mirror in the superior position, looking at 12 shows you 6, looking at 11 shows you 7, and looking at 1 shows you 5.
Now, let's say you want to look at something at 8. There are basically three ways to do it.
(1) You can have the mirror centered on 2, and 8 will be directly across from the center, and that's the easiest way to picture it.
(2) You can have the mirror centered on 1, but look at the 12 position.
(3) Or you can have the mirror centered on 3, but look at the 4 position.
All three of these approaches will show you the 8 o'clock position. The good side of that is that you have options for how to do something. The downside of it is that it's easy to overthink it and confuse yourself.
It helps if you draw it out, and move a mirror around your drawing.
