Foreign Body Sensation

  • Sensation of having "sand in my eye"
  • Often accompanied by photophobia (abnormal sensitivity to light)
  • Caused by exposure of corneal trigeminal nerve endings because of surface epithelial defect
  • Common causes: traumatic abrasions (from corneal or conjunctival foreign bodies), surface erosions from drying, exposure, infection
  • Corneal light reflection may be broken up
  • Cornea may lose transparency in some areas, which appear gray or white
  • Corneal limbus may be hyperemic ("ciliary flush")
  • Topical fluorescein staining may reveal green areas of dye uptake
  • "Scratchy" sensation associated with inflamed conjunctiva
  • "Itchy" sensation associated with ocular allergy
  • "Aching"  associated with intraocular inflammation, elevated eye pressure, or inflammation of soft tissues surrounding or behind eye
  •  "Sharp" pain associated with trigeminal autonomic cephalalgias
  • "Stabbing" (lancinating) pain associated with trigeminal neuralgia
  • Define the symptom as well as possible
  • Instill topical anesthetic, which will eliminate foreign body sensation if caused by a corneal surface erosion
  • Inspect cornea for abnormal reflection, turbid areas, corneal foreign bodies
  • Instill fluorescein dye and look for green spots
  • If fluorescein staining is positive, do not forget that foreign body may be lurking under upper lid;  evert lid to hunt for it
  • Mild traumatic corneal abrasions heal quickly; if that does not happen within 24 hours, refer to ophthalmologist
  • If there is no hint of trauma (including prolonged contact lens wear), refer promptly to ophthalmologist to rule out other causes