Amazon is adding new lens options to its Echo Frames smart glasses to add flexibility.

Previously, Echo Frames were only available with clear lenses, but soon users will be able to customize their smart glasses with a choice of sunglass lenses (classic and blue mirror lenses). The classic lenses are available now, while the blue mirror finish will be available on June 9.

All new lenses will come with the classic black frames and will be available for $269, adding $20 to the MSRP of the standard Echo Frames. Amazon has previously made the Echo Frames degree-ready, but this is the first time that degree-less lenses will be available for customization prior to purchase.

The classic sunglass lenses have a fairly standard black/brown tint, while the blue mirror finish is more flashy. Blue light filter lenses are a more practical approach, aimed at reducing the amount of blue light entering the eye from digital screens.

All three options come with the existing Echo Frames v2 frame, bringing a familiar feature set, including IPX4 water resistance and a built-in speaker for playing music via Bluetooth. The built-in Alexa digital assistant also allows users to give commands and make inquiries using the onboard microphone while keeping both hands free. When paired with a phone, Echo Frames can also be used as a headset for calls.

In our review of the Echo Frames v2, we praised the comfort and (mostly) good looks of Amazon's smart glasses, the latter of which will look even better (in the eye of the beholder, of course) with this new set of lenses. However, the sound quality from the open speakers proved lacking compared to the Bose Frames.