Yes, poor posture can cause eye strain. Slouching or leaning forward can lead to neck, shoulder, and back pain, contributing to the discomfort often attributed to eye strain. Poor posture can also result in improper viewing angles and distances from screens or reading materials, exacerbating eye strain. For example, tilting your head or leaning forward to see better can cause muscle tightness and fatigue in the neck and shoulders, further contributing to eye strain.