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DR. VASDEV HARANI
 Associate Professor
   Ophthalmology
Introduction to the Eyeball
Eyelids
Conjunctiva
Cornea
Sclera
Uveal tract
Aqueous humor
Anterior chamber angle
Lens
Retina
Optic nerve
A spherical globe with a diameter of 24.5mm.
Consists of
   Skin
   Subcutaneous tissue
   Orbicularis muscle
   Levator palpebrae superiorus
    (upper lid)
   Tarsal plate
   Palpebral conjunctiva
   Protect the eye from injury

   Reflex closure of eyelids occurs
    when some object comes close to
    the eye or bright light shines into
    eye (corneal reflex)

   Regular blinking assists in
    distribution of tears and prevents
    drying of the tear film
A transparent mucous membrane that lines the inner surfaces of
    the eyelids and the front surface of the eyeball.
The Palpebral conjunctiva
   Starts at the lid margins and
      is firmly attached to the
      posterior tarsal plate
The Fornical conjunctiva
    Is loose and redundant and
        maybe thrown into folds
The Bulbar conjunctiva
    Covers the anterior sclera and
    is continuous with the corneal
        epithelium at the limbus
   Epithelium
     is non-keratinizing and about five cell
      layers thick
     Basal cuboidal cells evolve from the
      surface
     Goblet cells are located within the
      epithelium
   Stroma
     Consists of richly vascularized loose
      connective tissue
     Accessory lacrimal glands of Krause
      and Wolfring are located deep within
      the stroma
   The transparent dome
    which serves as the
    window of the eye.

   The primary (most
    powerful) structure
    focusing light entering
    the eye.
Cornea is composed of 5
  layers
    Epithelium.
    Bowman’s membrane.
    Stroma
    Descemet’s membrane.
    Endothelium).
   No blood vessels.
   Transparent stroma with low level of fluids.
     Endothelium  cells serves as a pump that supply oxygen and
      remove fluids.
   Tear film also supplies oxygen and keep corneal
    surface smooth and clean.
   The white, opaque cover of the
    eye.
   Covers 80% of the eye’s outer
    layer.
   Contains thick elastic collagen.
   It provides protection.
   Serves as an attachment for the
    extra-ocular muscles which
    move the eye.
   Iris
   Ciliary body
   Choroid
   The iris is composed of
     Endothelium
     Stroma
     Epithelium




   Stroma muscles
     Dilator - sympathetic innervation
     Constrictor – parasympathetic
      innervation
   Determined by the amount of pigment
    present in iris.

   No pigment - pink iris (albino), some
    pigment – blue iris, increasing amounts of
    pigment- green>hazel> brown irides. 

   The pigments: melanin (chromosome 15)
    and lipochrome (chromosome 19).

   Heterochromia irides: when one iris has a
    different color than the other iris.
   The pupil is the clear area that is located in
    the center of the iris of the eye.

    It appears black because most of the light
    entering the pupil is absorbed by the
    tissues inside the eye

   In darkness the iris dilator muscle causes
    the pupil to “dilate” and allowing more
    light to reach the retina.

   In brightness, the iris sphincter muscle
    (which encircles the pupil) constricts,
    causing the pupil to “constrict” and
    allowing less light to reach the retina.
   Constriction also occurs during accommodation
    - the “near reflex.”
   Pars plana – flat area
    continuous with the retina

   Pars plicata – contains the
    ciliary processes that secretes
    the aqueous humor

   Ciliary muscle runs circularly
    around the eye and controlles
    accommodation
   The posterior segment of the uvea, between the sclera and the
    retina.
   Reach in blood supply, supplies oxygen and nutrition to the
    outer two thirds of the retina.
   Produced by the ciliary
    body.

   Entering from the posterior
    chamber, it passes through
    the pupil into the anterior
    chamber and filtrates
    through the angle into the
    blood stream.

   Serves to nourish ocular
    structures.
   Iris-corneal junction

   Contains the trabecular meshwork
    (TM )which acts like a filter for the
    aqueous humor.

   From the TM the humor drains to
    schlem’s canal and then to blood stream.
   Biconvex, avascular,
    transparent structure.

   Suspends behind the iris by
    the zonules which are
    connected to the ciliary body.

   Serves to converge light onto
    the retina.
   Ciliary muscle constrict >
    zonular tension decreases > lens
    becomes more spherical >
    more dioptric power that
    converge light from a near
    target onto the retina.
   This loss of transparency, or opacity formation is called
    Cataract
   The innermost layer of the eye.

   The retina is a multi-layered
    sensory tissue that lines the
    back of the eye. 

    It contains millions of
    photoreceptors that capture
    light rays and convert them
    into electrical impulses. 

    These impulses travel along
    the optic nerve to the brain
    where they are turned into
    images.
   Fovea: area with the highest concentration of photoreceptors.
   Central retina: A circular field of approximately 6 mm around the
    fovea.
    Peripheral retina: stretching to the ora serrata.
Phptoreceptors
  Cones
     Concentrated in the fovea
     Most active in daylight
     Central vision
   Rods
     Mostly in the peripheral
      retina
     Most active in night vision
     Peripheral vision
   Consists of 1.2 million axons that arise from the retina.
   Leaves the eye through the optic disc also known as the blind
    spot.
Anatomy of the eye for studentss

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Anatomy of the eye for studentss

  • 1. DR. VASDEV HARANI Associate Professor Ophthalmology
  • 2. Introduction to the Eyeball Eyelids Conjunctiva Cornea Sclera Uveal tract Aqueous humor Anterior chamber angle Lens Retina Optic nerve
  • 3. A spherical globe with a diameter of 24.5mm.
  • 4. Consists of  Skin  Subcutaneous tissue  Orbicularis muscle  Levator palpebrae superiorus (upper lid)  Tarsal plate  Palpebral conjunctiva
  • 5. Protect the eye from injury  Reflex closure of eyelids occurs when some object comes close to the eye or bright light shines into eye (corneal reflex)  Regular blinking assists in distribution of tears and prevents drying of the tear film
  • 6. A transparent mucous membrane that lines the inner surfaces of the eyelids and the front surface of the eyeball.
  • 7. The Palpebral conjunctiva Starts at the lid margins and is firmly attached to the posterior tarsal plate The Fornical conjunctiva Is loose and redundant and maybe thrown into folds The Bulbar conjunctiva Covers the anterior sclera and is continuous with the corneal epithelium at the limbus
  • 8. Epithelium  is non-keratinizing and about five cell layers thick  Basal cuboidal cells evolve from the surface  Goblet cells are located within the epithelium  Stroma  Consists of richly vascularized loose connective tissue  Accessory lacrimal glands of Krause and Wolfring are located deep within the stroma
  • 9. The transparent dome which serves as the window of the eye.  The primary (most powerful) structure focusing light entering the eye.
  • 10. Cornea is composed of 5 layers  Epithelium.  Bowman’s membrane.  Stroma  Descemet’s membrane.  Endothelium).
  • 11. No blood vessels.  Transparent stroma with low level of fluids.  Endothelium cells serves as a pump that supply oxygen and remove fluids.  Tear film also supplies oxygen and keep corneal surface smooth and clean.
  • 12. The white, opaque cover of the eye.  Covers 80% of the eye’s outer layer.  Contains thick elastic collagen.  It provides protection.  Serves as an attachment for the extra-ocular muscles which move the eye.
  • 13. Iris  Ciliary body  Choroid
  • 14. The iris is composed of  Endothelium  Stroma  Epithelium  Stroma muscles  Dilator - sympathetic innervation  Constrictor – parasympathetic innervation
  • 15. Determined by the amount of pigment present in iris.  No pigment - pink iris (albino), some pigment – blue iris, increasing amounts of pigment- green>hazel> brown irides.   The pigments: melanin (chromosome 15) and lipochrome (chromosome 19).  Heterochromia irides: when one iris has a different color than the other iris.
  • 16. The pupil is the clear area that is located in the center of the iris of the eye.   It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye  In darkness the iris dilator muscle causes the pupil to “dilate” and allowing more light to reach the retina.  In brightness, the iris sphincter muscle (which encircles the pupil) constricts, causing the pupil to “constrict” and allowing less light to reach the retina.  Constriction also occurs during accommodation - the “near reflex.”
  • 17. Pars plana – flat area continuous with the retina  Pars plicata – contains the ciliary processes that secretes the aqueous humor  Ciliary muscle runs circularly around the eye and controlles accommodation
  • 18. The posterior segment of the uvea, between the sclera and the retina.  Reach in blood supply, supplies oxygen and nutrition to the outer two thirds of the retina.
  • 19. Produced by the ciliary body.  Entering from the posterior chamber, it passes through the pupil into the anterior chamber and filtrates through the angle into the blood stream.  Serves to nourish ocular structures.
  • 20. Iris-corneal junction  Contains the trabecular meshwork (TM )which acts like a filter for the aqueous humor.  From the TM the humor drains to schlem’s canal and then to blood stream.
  • 21. Biconvex, avascular, transparent structure.  Suspends behind the iris by the zonules which are connected to the ciliary body.  Serves to converge light onto the retina.
  • 22. Ciliary muscle constrict > zonular tension decreases > lens becomes more spherical > more dioptric power that converge light from a near target onto the retina.
  • 23. This loss of transparency, or opacity formation is called Cataract
  • 24. The innermost layer of the eye.  The retina is a multi-layered sensory tissue that lines the back of the eye.    It contains millions of photoreceptors that capture light rays and convert them into electrical impulses.   These impulses travel along the optic nerve to the brain where they are turned into images.
  • 25. Fovea: area with the highest concentration of photoreceptors.  Central retina: A circular field of approximately 6 mm around the fovea.  Peripheral retina: stretching to the ora serrata.
  • 26. Phptoreceptors  Cones  Concentrated in the fovea  Most active in daylight  Central vision  Rods  Mostly in the peripheral retina  Most active in night vision  Peripheral vision
  • 27. Consists of 1.2 million axons that arise from the retina.  Leaves the eye through the optic disc also known as the blind spot.