Credit: Joe Maring / Android AuthorityTL;DROne smart glasses brand plans to charge a subscription fee for its AI features.The L’Atitude 52°N Berlin smart glasses will cost $399, but their best features are only free for the first 12 months.Kickstarter backers will get lifetime AI access, but post-launch buyers will face an as-yet-unknown recurring charge.Smart glasses are still very much a niche category of wearable that most people are currently happy to watch from a safe distance. Some people understandably think they’re a bit creepy, but even for those who find them intriguing as a concept, you probably need a pretty good reason to actually buy a pair. One company may have just offered the opposite, as the new L’Atitude 52°N Berlin smart glasses only include their AI features for 12 months before a paid subscription kicks in if you want to keep them. The Berlin glasses go on sale on May 26 for $399 (via Wired), with photochromatic lenses costing an additional $50. That would be all well and good, but not only does a subscription kick in after one year, L’Atitude 52°N still hasn’t said how much it will be. We only know that buyers who don’t pay up after the first year will be limited to base features such as music playback and media capture.