Chapter 57: Adult Eye and Ear Problems

The eye is a roughly spherical organ composed of three functional layers: an external protective layer including the cornea and sclera, a middle vascular layer housing the iris and ciliary body, and an internal neurosensory layer containing the retina with its specialized photoreceptors for vision. The retina contains rod cells responsible for peripheral and dim-light vision and cone cells that enable central, color, and bright-light vision, with the sharpest visual acuity occurring at the fovea centralis. Intraocular pressure, maintained between 10 and 21 millimeters of mercury through aqueous humor circulation and drainage via the canal of Schlemm, is critical for preserving normal eye structure and function. Diagnostic assessment of ocular health involves specialized procedures such as tonometry to measure pressure, fluorescein angiography to visualize blood vessel perfusion, slit lamp examination for detailed anterior segment inspection, and corneal staining to detect surface irregularities. Common refractive errors including myopia, hyperopia, presbyopia, and astigmatism affect how the eye focuses light. Cataracts, glaucoma, retinal detachment, and macular degeneration represent progressive ocular diseases requiring distinct nursing interventions and patient education focused on preventing further vision loss. Eye trauma management varies by injury type, from chemical burns requiring immediate irrigation to penetrating objects that must never be removed before professional evaluation. The ear facilitates both hearing and vestibular balance through its tripartite structure: the external ear, the middle ear containing the three ossicles that transmit vibrations, and the inner ear housing the cochlea for sound processing and semicircular canals for equilibrium. Hearing loss manifests as either conductive loss from mechanical obstruction or sensorineural loss from neural damage, with presbycusis representing age-related decline in auditory function. Common ear pathologies including otitis media, mastoiditis, otosclerosis, Ménière's syndrome, and labyrinthitis require nursing care emphasizing safety, infection monitoring, and communication facilitation strategies such as facing the patient and speaking in lower-pitched tones.