Eye contact rule, when do know if it’s a sign?

So I see a lot of guys on here saying that if you make eye contact with a girl or if you catch her looking at you then it’s a sign to approach her.

Is this true? Like in my college I see a ton of cute girls and sometimes I will either catch them looking at me or we will just look at each other.

I never do anything though lol I always look away but is that really a sign that I should approach them? Because it happens to me like every day almost.