How to use "at first glance"

image from here

When you first see someone or think about something without having more details, you may say "at first glance" . It's your first impression. Let´s look at some examples?

At first glance the deal looked wonderful, 

but after reading the fine print he wasn’t so sure. 

At first glance, the problem appeared quite simple. 

Later we learned just how complex it really was. 

At first glance, the theory seems to make a lot of sense.