how much can you really tell about someone from their eyes, facial expressions, and overall vibe?

Sometimes I feel like I can look at someone and immediately get a sense that they’re carrying certain emotional struggles or personality traits. Like i can looking at your eyes that you’re a narcissist and have anger issues.
Other times I wonder if I’m just projecting or relying on intuition that isn’t actually reliable.(is female intuition a thing?)

Is there any truth to these gut feelings, or is this similar to psychological effects where we see patterns and meanings that could apply to almost anyone? I’d be interested to hear other people’s experiences and opinions.