Ridge Vents and Shingles... Required on top?

I bought a nice little drone and decided to fly it around. I just noticed 18 months after we built our house, the roofers never put shingles on top of the ridge vents. Is this a big deal or just aesthetics? I flew over the neighborhood and it appears I am the only house with this little issue. Do I need to get them out here to finish or can I just leave it be? It's 18 months later, so I may have issues is why I am asking.