There are specific vision indicators as you have already noticed but you cannot tell whether somthing is true vision (ignores stealth) or just a normal vision (ignores fog of war / bushes). This depends entirely on the spell that is cast.
A Nidalee trap grants vision to a stealthed target and it used to have the same indicator (second picture) as Corkis Phosphorous Bomb (Does not reveal stealth).
If you see such a thing above your head it basically just means that the enemy has vision on this champion.
Here you can find a list with all stealth detection methods.
Here you can find a list of all vision generating spells. You will notice some of them use the same Icon as stealth detecting ones.
The following Champion spells use individual "marks" for vision.
The ones not listed use the standard "eyes" that look like this
Diana Q (Champion is pierced by a ray of dim light, does not reveal stealth)
Warwick E (Two Red eyes, Does not reveal stealth)
Twisted Fate R (Orange Eye, Does reveal stealth)
Talon Q (Blade above the target, Does not reveal stealth directly but prevents from entering it due to ticking damage)
Nidalee Passive (A yellow triangle, Does reveal stealth)
Rengar R (Not really a mark, but the champion glows red, reveals stealth)