The synonym for "more squinteyed" could be "more narrow-eyed." This would describe someone whose eyes appear more closed or slightly distorted due to an intense focus or scrutinizing gaze. Another option could be "more piercing-eyed," which suggests a sense of sharpness or depth to one's gaze. "Squintier" or "more narrowed" could also be used as synonyms, which imply a tighter, more compressed appearance to the eyes. Additionally, "more attentive," "more perceptive," or "more observant" could be used to describe someone who is highly focused or aware of their surroundings.