The aims of this study: 1) to determine postural changes according to wearing glasses and relationship between these changes and deep cervical flexor muscle group, 2) to investigate effectiveness of endurance training on postural changes and deep cervical flexor muscles. Seventy-three patients who had neck pain participated in this study and divided into two groups according to wearing glasses or not. Before and after endurance training for 6 weeks, postural angles of cervical region were counted, deep cervical flexor endurance test was performed and score of pain and disability index were noted of all subjects. Before treatment endurance levels were lower and scores of disability index were higher in experimental group (p< 0.05). After treatment endurance levels were improved, and scores of disability index were decreased more significantly in control group (p< 0.05). There were no significant differences between gaze, head and neck angles in both groups after treatment (p> 0.05). As a result it was seen that wearing glasses affected endurance of deep neck flexor muscles negatively, and it was not found relationship between postural angles and endurance of deep cervical flexor muscles. Also it was observed that endurance training for 6 weeks hadn't affected postural angles but enhanced performance of deep cervical flexor muscles significantly.