NEW YORK—With Memorial Day just around the corner, many of us are thinking about summer parties already. Planning a Memorial Day celebration can be overwhelming. There’s so much to take into account: the guest list, the food, the decorations, the drinks. Thankfully for all us optical-nerds, there’s no shortage of fun ways to inject a little optical joy into our parties alongside the abundance of American flags, and getting the party planning out of the way early means more time to relax and commemorate this Memorial Day Weekend, which is as good a reason as any to get shopping now. Here’s a roundup of some of our favorite optical treats to help make your Memorial Day, no matter what you’re planning, stand out.