I think the optical stream fits more of an error correction/secondary data stream in this case. The difficulty may be down to you trying to use other senses an

I think the optical stream fits more of an error correction/secondary data stream in this case. The difficulty may be down to you trying to use other senses and overcompensating on the data (e.g. air pressure, which tells you something is near-ish you but not if it's about to contact you so you react)