In summary.... read the measure from both ends. See the simple pattern at the end if it is there. See the complex pattern not as individual notes but as a pattern that you have already learned to play. Learn a lot of patterns, and you can sight read many pieces of music with accuracy. Remember that you can only "attend to" a maximum of 7 things at a time. Included in those seven things could be tone, dynamics, breathing, tempo, following the director, accents, key signature, time signature.... hey we're past seven. So how in the world can anybody play an instrument? Simple.... automatic performance controlled by the subconscious mind. If you learn the basic skills to the point of automatic performance... then you can attend to the things that are not automatic. And you can attend to the things that make music art.
Learn your rhythmic patterns so you recognize them automatically. Mark the tricky spots on your music so you will remember to read them. Have you ever been playing a piece and suddenly lost your place for no apparent reason? It happens to all of us and is usually because we have been on auto-pilot for a while and suddenly we are in unfamiliar territory and didn't make the switch in our attention. The admonition "read ahead" really means "scope out the territory."
So... when on auto-pilot, be sure to pay attention to where you are. Learn patterns. Read patterns. Play patterns. Use the bar lines as "mile posts on the interstate." Constantly redirect your attention and focus.