THE EYES

• CONJUCTIVA


  clear mucuos membrane with 2 easily visible components.
• 2 types of conjunctiva

  1. bulbar conjunctiva / sclera

  2. palpebral conjunctiva
• structures of eye

  1. upper eyelid

  2. sclera covered by conjunctiva

  3. lateral canthus

  4. limbus

  5. lower eyelid

  6. iris

  7. pupil

  8. medial canthus
• tarsal plates

  within eyelids lie firm strips of connective tissue
• levator palpebrae


  muscle raises the upper eyelid, is innervated by the oculomotor nerve, cranial nerve III
• LACRIMAL PUNCTA


  tear fluid spreads across the eye and drains medially through two tiny holes. Tears pass into the lacrimal sac and into the nose through the nasolacrimal duct.
• vitreous humor


  clear gel fills the anterior and posterior chambers of the eye.
• aqueos humor


  clear liquid fills the anterior and posterior chambers of the eye, circulating between the cornea and lens. Produced by ciliary body circulates from posterior chamber through the pupil into the anterior chamber, and drains out through the canal of schlemm.
• fundus of the eye


  posterior part of the eye seen through ophthalmoscope
• parts of the fundus

  1. retina

  2. choroid

  3. fovea

  4. macula

  5. optic disc

  6. retinal vessels
• vitreous body


  HELPS MAINTAIN THE SHAPE OF THE EYE

  TRANSPARENT MASS OF GELATINOUS MATERIAL THAT FILLS EYEBALL BEHIND THE LENS.
• visual fields


  entire area seen by an eye when it looks at a central point. the center of the circle represents focus of gaze
• visual pathways


  to see an image, light reflected from the image must pass through the pupil and be focused on photoreceptors in the retina.
• the near reaction


  - occurs when a person shifts gaze from a far object to a near object and the pupils constrict

  - medicated by the oculomotor nerve (CN III)
• extraocular movements


  eye movements controlled by several pairs of eye muscles
• 6 cardinal directions

  SUPERIOR RECTUS ( CN II)

  LATERAL RECTUS ( CN VI)

  MEDIAL RECTUS ( III)

  INFERIOR RECTUS ( CN III)

  INFERIOR OBLIQUE III

  SUPERIOR OBLIQUE IV
• COMMON OR CONCERNING SYMPTOMS

  1. changes in vision

  2. double vision or diplopia

  3. strabismus

  4. blurring

  5. redness

  6. itching

  7. discharge

  8. pain

  9. tearing

  10. edema

  11. lesions

  12. visual disturbances

  13. photophobia

  14. use of corrective lenses ( glasses/ contacts)

  15. prosthesis
• changes in visions

  HYPEROPIA

  PRESBYOPIA

  MYOPIA

  SCOTOMAS
• HYPEROPIA (farsightedness)


  a refractive error, eyes does not bend / refract light properly
• PRESBYOPIA


  eyes gradually lose ability to see things clearly up close, normal part of aging, after the age of 40.
• MYOPIA (nearsightedness)


  see objects near to you clearly, but objects farther away are blurry.
• scotomas


  area of lost or depressed vision within vision field and is surrounded by an area of normal vision.
• strabismus


  eyes not lined up properly and point in different directions
• photophobia


  light sensitivity from excess light entering the eye, which may overexcite the photoreceptors in retina.
• RED EYES

  -conjunctivitis

  - subconjunctival hemorrhage

  -corneal injury or infection

  - acute iritis

  -acute angle closure glaucoma
• equipments needed for physical examination

  -eye chart

  - near vision card

  - index card or opaque covering

  - penlight

  - ophthalmoscope
• snellen test


  to test the aquity of central vision and the patient's ability to see at a distance, use a well-lit snellen eye chart
• the "E" chart


  used for testing the vision of children or people who are unable to read
• near vision tests


  test near vision with a special hand held card, hold 14 in away from the eyes, test identifies the need for reading glasses / bifocals
• CONFRONTATION


  comparison between the pt. and the nurse, the nurse has intact peripheral vision, to determine any areas of depicit.
• the visual field is ___ horizontally and ____ vertically.

  180 degree

  135 degree
• temporal field defects

  - HOMONYMOUS HEMIANOPSIA

  - BITEMPORAL HEMIANOPSIA

  - QUADRATIC DEFECTS
• VISUAL DEFECTS

  - HORIZONTAL DEFECT

  - BLIND RIGHT EYE ( RIGHT OPTIC NERVE )

  - BITEMPORAL HEMIANOPSIA ( OPTIC CHIASM)

  - LEFT HOMONYMOUS HEMIANOPSIA ( RIGHT OPTIC TRACT)

  - HOMONYMOUS LEFT SUPERIOR QUADRANTIC DEFICIT ( RIGHT OPTIC RADIATION, PARTIAL)
• HORIZONTAL DEFECT


  occlusion of a branch of the central retinal artery
• blind right eye ( right optic nerve)


  a lesion of the optic nerve and ofcourse of the eye itself, produces unilateral blindness.
• bitemporal hemianopsia (optic chiasm)


  may involve only fibers crossing over to the opposite side. visual loss involves the temporal half of each field.
• left homonymous hemianopsia ( right optic tract)


  visual loss in the eyes is therefore similar (homonymous) and involves half of each field ( hemianopsia)
• homonymous left superior quadrantic defect ( right optic radiation, partial)


  a partial lession of the optic radiation in the temporal lobe may involve only a portion of the nerve fibers, producing a homonymous quadrantic defect.
• left homonymous hemianopsia (right optic radiation)


  a complete interruption of fibers in optic radiation produces visual defect similar to that produces by a lesion of the optic tract.
• variation and abnormalities of the eyelids

  - PTOSIS

  - ENTROPION

  -ECTROPION

  - LID RETRACTION AND EXOPHTHALMOS