VISION LEARNING CENTER

- Clouding of the eye's naturally clear lens which blocks or changes the passage of light into the eye.

Risk Factors: - Age - Heredity - Eye Injuries - Inflammation in the Eye - Disease - Smoking - Steroid Use - Exposure to Intense Heat or UV Rays	Symptoms: - Blurred or Double Vision - Ghostly Images - Lighting Seems Dim or Dazzling - Changing Prescriptions Doesn't Help
	To avoid vision loss, have a complete eye exam every 1 - 2 years.
Cataracts are a leading cause of blindness in the United States. - More than 20 million Americans age 40 and older have cataracts. - By age 80 more, than 50% of Americans have cataracts.
More information can be found in the Prevent Blindness America Vision Learning Center.

- A complication associated with diabetes that causes the tiny blood vessels of the retina
to break down, leak, become blocked or abnormal new blood vessels to grow on the
surface of the retina. Vision is impaired over time.

Retina - Innermost layer of the eye that receives images and sends them to the brain.

Visit the Prevent Blindness America Vision Learning Center for: - Diabetes and Eyesight Quiz - Diabetic Retinopathy Vision Simulation - Basic Diabetes Facts - Risk Factors - Diagnoses and Testing - Stages of the Disease - Treatment of the Disease - Medicare Benefits - Other Resources

- A gradual degeneration of cells that make up the optic nerve. As nerve cells die, vision is slowly lost.
Significant nerve damage can occur before vision loss is noticed.

Optic Nerve - Nerve which carries messages from the retina to the brain, producing visual images.

Visit the Prevent Blindness America Glaucoma Learning Center for: - The Vision Risk Assessment - Glaucoma Eye Drops Information - Glaucoma Forum - Facts About Glaucoma - Risk Factors - Diagnosing Glaucoma - Eye Damage Information - Types - Treatment - Living with Glaucoma - Financial Assistance - Vision Care Resources

- A group of diseases that causes the retina to deteriorate.

RP causes the rods and cones in the retina that sense light to stop working at which point only a small tunnel of central vision remains.
Retina = Innermost Layer of the Eye Rods = Side and Night Vision Cones = Central and Color Vision
Symptoms: - Slow to adapt to dim light - Slow loss of side vision	RP affects approximately 400,00 Americans.
Treament: -Receive treatment from a low vision specialist. - Protect eyes from bright sunlight by wearing a hat or visor and sunglasses. There is currently no cure for RP.

- Inflammation of the uvea.

Uvea - The layer of the eye made up of the iris, ciliary body and the choroid.

Visit the Prevent Blindness America Uveitis Learning Center for: - Uveitis Facts - Causes - Symptoms - Diagnosing & Treating Uveitis - Living with Uveitis
Most common in the 4th decade of life.	More prevalent in women.

Amblyopia - "Lazy Eye"

- Reduced vision in an eye that has not received adequate use during early childhood.
- If not treated early enough, by approximately age 6, an amblyopic eye may never develop good vision
and may even become blind.

Signs of Amblyopia - Tilting the Head - Drifting of an Eye - Tendency to Close one Eye - Rubbing the Eyes - Excessive Blinking - Holding Objects very Close to the Eyes	Possible Treatments - Patching - Glasses - Eye Drops - Ointment - Surgery - Eye Exercises
Causes of Amblyopia - Strabismus - Unequal Refractive Errors - Cataracts - Ptosis	An estimated 2% to 3% of people suffer from Amblyopia.
More information can be found in the Prevent Blindness America Amblyopia Learning Center. Prevent Blindness America's Eye Patch Club is a support resource for children and families with amblyopia.

- A drooping upper eye lid that touches or partially covers the pupil of the eye.
- The brain suppresses the image of poorer quality coming from the covered eye causing a
permanent vision loss if the eye is not treated.

Retinopathy of Prematurity

- Changes in the blood vessel's of the eye's retina that can permanently impair vision in premature infants.

Strabismus - "Crossed Eye"

- A disorder in which the eyes are not straight or properly aligned.
- Misalignment results from failure of the eye muscles to work together.
- Misalignment may be in one or both eyes and may be constant or come and go.
- Children's eyes should be aligned by 4 months old.
- If left uncorrected, Strabismus could develop into Amblyopia.

Esotropia = Eyes Turning In Crossed Eyes	Exotropia = Eyes Turning Out Wall Eyes
Hypertropia = Eyes Turning Up	Hypotropia = Eyes Turning Down
Causess Birth Injuries Heredity Faulty Muscle Attachment Need for Glasses Excessive Farsightedness Illness	Possible Treatments Glasses Eye Drops Ointment Injected Medicine Surgery Eye Exercises
Approximately 2% of children have Strabismus. Half of them are born with the condition.
More information can be found in the Prevent Blindness America Strabismus Learning Center.

Astigmatism

- Blurred vision caused by the curvature of the cornea and/or lens that prevents
light rays from focussing on a single point on the retina.

Color Vision Deficiency

Who? An estimated... - 8% of Males - Less than 1% of Females Have Color Vision Problems.	When? - Most color vision problems are hereditary and present at birth. - As the eye's clear lens darkens or yellows with age. - Some medications and diseases can cause problems.
There is no cure for Color Vision Deficiency.

Conjunctivitis

"Pink Eye"
- Inflammation of the conjunctiva due to infection caused by a virus, bacteria,
allergic reaction or chemical irritation.
- Usually affects both eyes.
- Most common eye infection in the United States.

Conjunctiva - the clear mucous membrane that covers the white part of the eyeball and the inside of the eyelid.

Eyes May Be: - Red - Itchy - Irritated - Swollen - Sensitive to Light - Sticky due to Dried Mucous	Treatment: - Antibiotic eye drops, ointments or other medications. - Clean crusting eyelids with a cotton swab and warm water. - Glasses are fine but eye patches can worsen the infection.
	More information can be found in the Prevent Blindness America Conjunctivitis Learning Center.

- Small spots that you may occasionally see in your line of vision.

Forms: - Dots - Threads - Cobwebs Floaters are seen as shadows by the retina.	Causes: - Small amounts of bleeding in the eye. - Vitreous that clumps together. - Small flecks of protein of other material that was trapped in the vitreous when the eye formed. Vitreous - a colorless mass of soft, gelatin material that fills the eyeball between the lens and retina.
When a floater appears move your eye around to shift the fluid. If a large number of floaters appear at one time and worse over time, contact a doctor.
	Treatment: Floaters are a normal part of the eye's aging process. Surgery is rare and only suggested for severe cases.

- A defect in the optics of the eye that result in the lack of precise focus of light rays on the retina.

Myopia	Nearsightedness
Distant objects are blurred due to light focussing in front of the retina.

Hyperopia	Farsightedness
Near Objects are blurred due to light focussing behind the retina. - Can cause fatigue and strabismus in children.

Retinal Tears and Detachments

- Retinal Tear - When vitreous fluid changes shape and pulls a piece of the retina with it.
- Retinal Detachment - When vitreous fluid seeps between the retina and the back wall
of the eye causing the retina to pull away.

Retina Innermost Layer of the Eye

Vitreous Fluid Gelatin Material that Fills the Eye

Symptoms: - Blind Spot - Blurred Vision - Shadowy Lines - Flashes of Light - Floaters	Risks: - Old Age - Inflammation - Myopia - Past Eye Surgery - Past Eye Injury - Family History - Diabetes
More information can be found in the Prevent Blindness America Vision Learning Center.

Conjunctive

- Clear mucous membrane that covers the white part of the eyeball and the inside of the eyelid.

Cornea

- Clear curved front of the eye through which light enters.

Optic Nerve

- Nerve of sight which carries messages from the retina to the brain, producing visual images.

Optic Disk - Head of the optic nerve.

Retina

- Innermost layer of the eye that receives images and send them to the brain.

Macula - The region of the retina that provides best central vision.

Fovea - Center of the macula.

Cones - Light-sensitive cells in the retina that provide central and color vision.

Rods - Light-sensitive cells in the retina that provide side and night vision.

Sclera

- White part of the eye. Tough covering that serves as a protective layer for the eye.

Uvea

- Layer of the eye made up of the iris, ciliary body and the choroid.

Iris - Colored circular membrane in front of the lens that controls the size of the pupil,
thereby regulating the amount of light entering the eye.

Ciliary Body - A ring of tissue consisting of muscles and blood vessels between the iris
and the choroid that changes shape of the lens and manufactures aqueous humor.

Choroid - Middle area of the eye containing blood vessels that provide nutrients.

Pupil - Opening in the center of the iris through which light enters the eye.

Aqueous Humor - Clear, watery fluid that fills the anterior and posterior chambers and provides
nutrients.

Anterior Chamber - Front portion of the eye between the cornea, iris and lens.

Vitreous Body

- Colorless mass of soft, gelatin material that fills the eyeball between the lens and the retina.