Anatomy External and internal eye structure: Eye lid :(upper and - - PowerPoint PPT Presentation

The Eyes

Randa M. Albusoul

School of Nursing

J U

Anatomy

External and internal eye structure:

Eye lid:(upper and lower) movable structure consist of skin and muscles . They protect eye from foreign body and limit amount of light enter eye. Eye lashes: projections of stiff hair that curve

• utward along the margin of eye lid. They filter

dust from air entering eye. Palpebral fisher Elliptical open space between the eyelids

Lateral(outer) and medial canthus: angle where lids meet, the “corner” Caruncle: is a small fleshy mass containing sebaceous gland at the inner canthus. Sclera: Outermost layer of the eye. It Is a dense, protective white covering that physically support internal eye structure and Maintains the shape of the eye and continuous anteriorly with cornea.

Cornea: (The window of the eye ). It is transparent to light and responsible for seventy percent of the total focusing of the eye. It is the most important layer in the refractive procedure and, together with the lens, forms a clear image on the back of the retina. Iris : Circular disc of muscle containing pigment that determine color of the eye. Less pigment makes the eyes blue; more pigment makes the eyes brown. Pupil: is the central opening of the iris. Muscles of the iris control size of pupil and thus amount of light entering eye.

Conjunctiva: transparent thin mucous membrane. Consists

• f:

Palpebral conjunctiva- clear, lines the lids with many small blood vessels. Bulbar conjunctiva (sclera) – overlays the eyeball. Lacrimal apparatus: consist of lacrimal duct and gland that lacrimate eye. The lacrimal gland locates in the upper outer corner of orbital cavity and produces tears. When the lids blink the tear wash cross the eye then drain in the puncta (opening in the upper and lower lid at inner canthus. The tear then drain to lacrimal sac and channeled into nasolacrimal duct to the nose

Extraoccular muscles: six muscle in the outer surface

• f each eye ball. They control eye movement to the six

dimensions.

• Muscles give the eye straight (superior, inferior, lateral,

medial rectus muscles) & rotary (oblique superior and inferior muscles) movement.

• Stimulated by 3 cranial nerves

(CN IV innervates the superior oblique muscle, CN VI Innervates the lateral rectus muscle, CN III the rest muscles).

• Conjugate movement – eyes move in parallel position or

axis, allowing the brain to see only one image at a time.

Visual fields: Is the entire area seen by an eye when it looks at a central point. The center of the circle represents the focus of gaze.

Pupillary light reflex: when one eye is exposed to bright light, a direct light reflex occur (direct reaction)(constriction of that pupil) and consensual light reflex (simultaneous constriction of the other pupil). Pupillary reactions:

The near reaction (fixation): when a person shifts gaze from a far

• bject to a near one, the pupil

constrict. Convergence of the eye (extraocular movement).

Accommodation: an increase convexity of the lenses caused by contraction of the ciliary muscles.

Subjective Data

Have you notice any changes in your eyes? Is your vision as good as previously? Any changes in vision? Hyperopia (farsightedness)

Myopia: the light that comes in does not directly focus on the retina but in front of it.

1- Vision difficulty.

• Any difficulty seeing or any blurring (unclear

image)?

• Come on suddenly or progress slowly?
• In one eye or both?
• constant or come and go?

Do spot move in front of your eyes? One or many? In

• ne or both eye?

Any halos (circle) / rainbows around object? Or rings around lights? Any blind spots? Any loss of peripheral vision? Any night blindness?

Abnormalities: Floaters( shades): common with myopia. not significant until it is acute sudden; R/T retinal detachment. Halos around lights occurs with acute narrow angle glaucoma. Scotoma blind spot in visual field surrounded by an area

• f normal or decrease vision R/T glaucoma, optic nerve

disorder.

Floaters

Scotoma Blurred vision

Cataract: is a clouding of the lens inside the eye which leads to a decrease in vision.

Glucoma

A condition of increased pressure within the eyeball, causing gradual loss of sight

2- Pain:

• Any eye pain?
• Come on suddenly?
• Quality – burning or itching…
• Sharp , stabbing or pain with bright light.

3- Strabismus, diplopia:

• Any history of crossed eyes? Now or in the past ?
• Does this occur with eye fatigue?
• Ever see double. Constant or come and go? In one eye
• r both?

 Abnormality;

• Strabismus: is a deviation in the anteroposterior axis of

the eye.

• Diplopia : perception of two images of a single object.

Diplopia

Strabismus

Do you experience any redness? Excessive tearing? Discharge (color)? Eyelid lesions? Infections? Are they seasonal? Did you have any eye trauma? Surgery? Eye infection? Retinal detachment? Macular degeneration?

When was your last eye examination? Do you wear glasses, contact lenses? When do you begin to wear them? Are they corrective

• r cosmetic? How do you care for your

contact lenses? Family history: any history of congenital eye disease? Cataract? Glaucoma? Diabetes? In your family Are you on any eye medications?

Objective Data

Vision test: Central visual acuity By using Snellen eye chart. We records result using the numeric fraction at the end of the last successful line read. 6/6 m 20/20 feet ; normal. *( First (top) number numerator indicates the distance where the patient stand.) * ( lower number is dominator the distance at which normal eye could have read the particular line.

 Near vision:

* For people over 45 years old with difficult reading. * Hold card in good light about 35 cm from eye (35/35 normal; 14/14 inch). * Test each eye separately, with glass on. * Or ask client to read from newspaper, magazines.

Test Visual Fields (peripheral vision):

• Confrontation test:

Compare the person's peripheral vision with your own.

• Position your self in front of the patient at his eye

level, 2 ft( 70 cm) away ..

• Direct client to cover one eye. with the other eye to look

straight at you.

• Cover your eye opposite to the person’s covered eye.
• Hold a pencil or your finger as a target midline between

you and the other person and slowly advance it in from the periphery in several direction.

Inspect external ocular structure: Position and alignment of the eye: any protrusion, sunken appearance? Eye brow: Symmetry, quantity, distribution, lesions. Eyelids and lashes: the upper eyelid overlaps the superior part of the iris and approximate completely with the lower eyelid. Intact skin, no redness or lesion, Eyelashes are evenly distributed and curve outward. Ptosis

Conjunctiva and sclera: moist, white. numerous small blood vessels, pink, no swelling, or lesions. Ask the pt to look up as you depress lower lid with thumb. Ask the pt to look to each side and down.

Cornea and lens: shine a light from the side across the cornea Look for smoothness & clarity and no opacities in lens. Iris: flat, round, regular shape & even color. Pupil: , symmetry, round, regular, & equal in size 3- 5mm. Anisocoria: different size pupil.

Lacremal apparatus: pressure on the puncta and slightly evert the lower lid, no excessive tearing.

Pupillary light reflex :

• Darken the room
• Ask person to gaze into the distance (dilates the pupil).
• advance alight in from the side and note the response

Normal: constriction of the same-sided pupil (a direct light reflex).

• Simultaneous constriction of the other pupil ( a consensual

light reflex)

• The rest size is 3,4-5 mm and decrease equally in response

to light ** R3/1= 3/1L**

** This indicates that both pupils measure 3 mm in the resting state and that both constrict to 1 mm in response to light. PERRLA: Pupils Equal, Round, Reactive to Light and Accommodation Abnormal:

• Dilated pupils, dilated fix pupil, constricted

pupil.

• Un equal or no response to light

• Nystagmus is a vision condition in which the eyes make

repetitive, uncontrolled movements, often resulting in reduced vision. These involuntary eye movements can

• ccur from side to side, up and down, or in a circular
• pattern. As a result, both eyes are unable to hold steady on
• bjects being viewed.
• Lid lag: a rim of sclera is visible above the iris with

downward gaze (hyperthyroidism). Extraocular muscles: 1-assess extraocular movement: normal conjugate movement in each direction.

2-Diagnostic position test (cardinal fields): Lead eyes thru the 6 cardinal positions of gaze appx 12 inches away.

3- convergence:

4- Corneal light reflex: stand appx. 12 inches away 30cm / shine the light directly on the eyes (tests parallel alignment) Normal – Light reflection - exact same spot on each eye.

5- cover- uncover test: may reveal a light muscle imbalance. Norm -eyes should maintain a fixed gaze when cover is removed.