Scientists have confirmed that extended periods of detrimental (17) screen exposure can give rise to a variety of vision and neurological disorders. This mounting apprehension (18) has led many technology companies to introduce blue-light filtering solutions or restructure employee work schedules by organising digital wellness sessions, acknowledging (19) the significance of appropriate screen distance and regular eye breaks. Staring at screens for more than eight hours can result in visual complications like retinal strain, and persistent headaches over time. Many software professionals who spend long hours in front of digital screens suffer (20) from these visual impairments. Positioning the screen at eye level without hunching forward and resting the eyes for five minutes every hour can reduce the risk considerably. Prolonged screen exposure can cause disruptions in the visual system including retinal fatigue and deteriorating eyesight. When a patient reports visual difficulties, a/an evaluation (21) is carried out through an eye examination or retinal scan. Rehabilitative (22) exercises are prescribed to address the damage. Patients are additionally advised to attend (23) vision therapy sessions, whenever necessary. Which of the following words can replace the word highlighted as (18) in the passage to make it contextually and grammatically correct?