It has been done successfully in the past. All you need to do is add the appropriate lens to focus further away. Here they used an optical flow sensor for obs

It has been done successfully in the past. All you need to do is add the appropriate lens to focus further away. Here they used an optical flow sensor for obstacle avoidance in a canyon. The closer to one side you got the faster the terrain would pass by the sensor. Allowing the UAV to self correct. See the last two pages: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2537&context=facpub https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=...