Swollen/ goopy eye

Son will be 3 weeks Monday. For the past 1.5 weeks, son has had a goopy eye (right eye). It’s a little swollen and will be matted/gunky when he wakes up. He’s had constipation issues and cries frequently from that or when his diaper is changed. White part of eye is not red and no fever. PA at doctor’s office hasn’t seemed concerned by it but it worries me. It’s stringy when he wakes up from a nap

You can see how swollen it is underneath his eye in this pic