Also, be certain there isn't a direct glare onto the eyes from either an overhead light or natural sunshine. How do you feel after working in your office all day? In case of layer dries out, the lens starts rubbing out. In general, lot some ways to deal with eyestrain. https://Jobzone.Labor.ny.gov/jz/views/jobzone/leaving_site.jsf?id=302&url=aHR0cHM6Ly93d3cudGhlcmFsaWZlLmNvbS9leWUtbWFrZXVwLWFuZC1kcnktZXllcy1ibGVwaGFyaXRpcy1tZ2Qv/YmFubmVyPTI0Jmxpbms9aHR0cHM6Ly9MYWxpZ2FsaXZlc3RyZWFtaW5naGQubmV0Lw