Sometimes when you measure an eye, it will wiggle between two pixel offsets. Example:
Here is what you should do to prevent eye wiggle from messing you up:
Ideally, to avoid eye wiggle entirely, F3+C to measure the eye as late as possible, like as close to possible before it breaks, or even after it breaks if you can remember what the pixel offset is.
The eye might still wiggle until the moment it breaks. You should make sure that you are zoomed in, looking at the eye for at a second before it breaks so you can tell if this happens.
If the eye wiggles until it breaks, F3+C and check both pixel offsets. For example, if the eye is wiggling between +3 and +4, F3+C and adjust the measurement to +3, then +4. If both pixel adjustments have the same top offset, with at least one of them saying 100% or 99.9%, then it’s most likely correct. If the two pixel adjustments disagree on the top offset, you should just pick an arbitrary adjustment and throw another eye (from a different position).
For example, if the top offset is 100% @ 220, 0 with +3, and 70% @ 220, 0 with +4, you can be very confident that 220, 0 are the true stronghold coords.
But, if the top offset is 100% @ 220, 0 with +3, and 100% @ 180, 30 with +4, you cannot be certain it’s either 220, 0 or 180, 30, so you should throw another eye.
You only need to do this is the eye wiggles back and forth between both pixels relatively evenly. If it’s mostly on +3, and flashes to +4 for only a few frames each bob, you can safely assume the eye’s true pixel offset is +3.
Here is the more detailed guide on pixel perfect eye measuring as a whole: