1) Spawn at Mark level Min(Planet, Wave). Core Eyes should spawn Mark Vs.
2) Give the Eye longer spacing between pulses (1-2 minutes maybe), but larger blocks of ships. This feels a lot more meaningful to a player and is less subtle. It also gives meaningful short windows for quick attacks.
3) Remove the EMP immunity. If we want to pay AIP to clear it out (since we already can with a nuke), that seems fair to me. While EMP'd, it doesn't spawn anything.
4) Rename the AI Eye to Sentry Eye, Monitor Eye, or something Eye. AI Eye is awkward and confusing. Players have nothing called an Eye, so if AI Eye means an Eye owned by the AI, it is redundant. If its name is actually AI Eye, then it's the AI's AI Eye, which is silly. And then there is the pronouncation: A Eye Eye. So odd. Ok, maybe I'm a little OCD about its name. But putting something else in front leaves room for new versions of the Eye that do other things like maybe: Guardian Eye (spawns Guardians instead), Shielding Eye (just like a basic Eye with much less health and makes all Guard Posts invulnerable until destroyed), or whatever.
Bonus) To get the same effect as the Eye, but in a different way, consider
this suggestion.
EDIT:
One idea, as came up around the time as the eye originally did, is having the existing eye be one kind, and have other eye types use different mechanics, but all be triggered in roughly the same way: blob detection.
I like this