I was recently using Google Assistant and I have observed that Google Lens is enabled on my phone (Redmi Note 5). My phone is running MIUI 9.5 and Android Nougat.
I am not sure if this is going to stay on my phone because I don't think it's an intentional rollout as Google lens standalone app which is available on play store is still not compatible with my phone. The new design of Google lens was rolled out to phones recently. Google lens can currently detect Text, Products, Books, Media, Places, Barcodes.
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