The vocabulary of eye care.

Short, plain-English definitions of the terms you will run into reading about digital eye strain. Each links to a longer page with related concepts.

• Digital eye strain

  A cluster of vision-related symptoms caused by prolonged use of digital devices — eyes that feel tired, dry, blurred, or sore, often accompanied by headaches and neck/shoulder tension.

• Computer vision syndrome

  A clinical term used interchangeably with digital eye strain, describing the constellation of eye, vision, and musculoskeletal symptoms from extended screen use.

• Ciliary muscle

  The small ring of smooth muscle inside the eye that contracts to change the lens shape for near focus and relaxes for distance vision.

• Myopia

  A refractive error in which distant objects appear blurred while near objects remain sharp, caused by an elongated eyeball or excess corneal curvature.

• Presbyopia

  The progressive loss of near focus that begins in the early forties, caused by stiffening of the eye's lens and ciliary apparatus.

• Dry eye syndrome

  A chronic condition in which insufficient or poor-quality tears fail to keep the ocular surface lubricated, producing a burning, gritty, or scratchy sensation.

• Accommodation

  The eye's ability to change focus between objects at different distances, achieved by the ciliary muscle reshaping the crystalline lens.

• Blink rate

  The number of times the eye blinks per minute; normally around 15 in adults, dropping to 4 to 5 during focused screen use.