National Institute for Occupational Health and Safety research has found that overall levels of musculoskeletal discomfort and eyestrain are significantly reduced when structured conventional breaks (e.g. 15 minute morning and afternoon break) were also supplemented with 5 minute computer breaks after every 60 minutes. See resource here 

Note: More frequent breaks  are needed people experiencing pain (e.g. 5 minutes every 30 minutes). A health care professional can assist with providing break patterns necessary for optimal pain management.