Seeing is Believing
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Transcript of Seeing is Believing
Seeing is Believing
The Importance of Good Vision for Children
Dr. Teri Geist, ODNebraska Optometric
Association
Good Vision Means Better Learning
• Vision is a dominant process in growth, development and daily performance of children
• Undetected, untreated vision problems can interfere with students’ learning potential. Nearly 75% of the school day is spent on visual activities.
• Vision disorders are 4th most common disability in U.S.
Courtesy of AOA Clinical Practice Guidelines on Pediatric Examination
Good Vision Means Better Learning
• Only 15% of children have had an eye exam by age 5
• Only half of all children will have an eye examination before completing high school
• 75,000 3-year-olds develop amblyopia each year • Vision deficiencies in school age children are often
misidentified as behavior or social problems, which my put the child into the wrong “treatment track”.
• More than 75% of juvenile offenders have undetected and untreated vision problems.
Courtesy of AOA Clinical Practice Guidelines on Pediatric Examination
Statistics
• 60% of students identified as problem learners have undetected vision problems.
• Based on that, as many as 4,500 Nebraska children enter school each year with vision problems significant enough to hinder their ability to learn!!
Statistics courtesy of AOA
Role of Vision In Learning
• Vision occurs in the brain, not in the eyes • The eyes must see clearly, without double vision,
and with accurate focus control• The brain must interpret the visual image from its
background, make assumptions as to its figure, and integrate the information gathered from peripheral vision and from other senses
• A child must have visual ability to learn to read prior to reading to learn
Signs of a Visually Related Learning Problem
Frequent rubbing of the eyes
Frequent blinking of the eyes
Short attention span or frequent daydreaming
Poor reading
Avoiding close work
Frequent headaches
A drop in scholastic or sports performance
Signs of a Visually Related Learning Problem
ContinuedCovering one eye
Tilting the head
Squinting one or both eyes
Placing head close to book or desk when reading or writing
Difficulty remembering, identifying and reproducing geometric forms
Poor eye-hand coordination skills
What is good vision?
Good vision includes:– Visual acuity– Eye health– Eye teaming– Eye focusing– Eye motility
Vision Screenings
• Designed to identify gross visual problems and to indicate the immediate need for an eye examination. Parents must follow through on the referral.
• Most children who fail a vision screening will also fail a diagnostic professional examination
Visual AcuityHow clearly one sees
– Near vision- the ability to see at 8 -16 inches (reading a book)
– Intermediate vision- the ability to see at 16 -40 inches (computer distance)
– Distance vision- the ability to see at 10 feet or more
– 20/20 indicates that you can see letters 3/8” high at 20 feet
Components of Visual Screenings
Distance Visual Acuity– Purpose-To test for myopia, amblyopia,
astigmatism, and high hyperopia– Equipment-Distance VA chart and Occluder– Visual Acuity Charts Include:
• Snellen Chart• Tumbling E chart• Lea symbols
Snellen Chart & Tumbling E
Photos Courtesy of POA
Near Visual Acuity• Purpose- To test for hyperopia, astigmatism,
amblyopia, and focusing problems• Equipment- Near Acuity Cards and Occluder• Near Acuity Cards include:
– Snellen– Lighthouse acuity– Lea Cards– Tumbling E
Near point cards
Photos courtesy of POA
LEA Symbol Charts
Photos courtesy of POA
Eye Teaming Ability of the eyes to: • work properly together• to coordinate and align both eyes to
allow brain to fuse a single image from the images it receives from each eye
• to judge relative distances of objects and have depth perception
• to converge on something near by turning towards each other
Eye Focusing
• The ability of the eyes to focus and shift focus to near and distant points accurately and efficiently
Eye Motility • The ability of the eyes to move from one point to
another• The ability of the eyes to move across a page of
print or to follow a ball, etc…
Myopia (Nearsightedness)
• The inability to see distant things well• The eye is too long for the normal focusing
power of the eye• Symptoms include:
– Squints– Gets close to the board
Hyperopia (farsightedness) • The ability to see at all distances with additional
focusing effort
• Eyeball is too short for normal focusing power of the eye
• In children the lens can focus and accommodate through this error providing both clear distance and near vision, but much effort must be used. This can cause headaches, fatigue, and even crossed eyes.
• Symptoms Include:– Rubs Eyes– Has watery eyes– Complains of blurred vision
Astigmatism• Results from an irregular shape of the front
surface of the cornea.• The eye is more football shaped rather than
round• Causes blurred vision for distant and close-up
things• Symptoms include:
– Rubs eyes– Has watery eyes– Complains of blurred vision
Strabismus
• Occurs when the eyes are not aligned when viewing an object
• The eye may turn inward toward the nose (esotropia) or outward toward the side (exotropia)
• This is usually caused by poor muscle control • An eye turn can happen constantly or
occasionally
Esotropia
Exotropia
Symptoms of Strabismus
• Intermittent double vision• Closes or covers one eye• Says letters or words appear to move• Loses place• Is Inattentive• Rubs eyes• Has watery eyes• Complains of blurred vision• Has poor reading comprehension
Accommodative & Binocular Disorders
• Accommodative- The eyes cannot focus well
• The inability to contract or relax the eyes’ focusing muscles efficiently
• Binocular – The eyes do not work well as a team; for example, the eyes cannot converge for up-close reading
Accommodative Symptoms
– Headaches– Tired at the end of the day– Has blurred vision when looking from board
to book or book to board– Holds things very close– Is Inattentive– Rubs eyes– Has watery eyes– Complains of blurred vision– Has poor reading comprehension
Binocular Disorder Symptoms• Headaches• Fatigue• Double vision• Blurriness• Watery eyes• Rubs Eyes• Is Inattentive• Loses place• Says Letters or words appear to move
Amblyopia
• Also known as “lazy eye”• Reduced vision in an eye that was not
stimulated in early childhood• Can result from strabismus or misaligned eyes
or a difference in clarity between the two eyes• One eye is focusing better than the other
one• One eye becomes stronger from its use
and the other eye is suppressed and not worked hard enough
Color Vision Test
• Detects difficulty in ability to recognize color• Children with color deficit are not actually
blind to color, but simply have difficulty identifying and distinguishing between different colors
• Color Deficiencies are usually hereditary and affect 1 in 12 boys but only 1 in 200 girls
Color Vision Tests
Photos courtesy of POA
Color Vision Test• Equipment:
– Occluder– Pseudo-
Isochromatic Test Plates
• Referral Criteria– Student fails if
does not correctly identify the image on the card
Photos courtesy of POA
Convex Lens Test
• Detects large amounts of hyperopia• Equipment
– Age-appropriate distance acuity charts– Occluder– Pair of +2.25 Spherical Lens (ages 5-8)– Pair of +1.75 Spherical Lens(>age 8)
Convex Lens Test Referral Criteria
• If the student cannot read the 20/40 line while wearing the lenses then he/she has passed the test
• If the student can read the 20/40 line while wearing the lenses then the student has failed and should be referred.
Stereo/Depth Test
• Tests for amblyopia, strabismus, and binocularity
• Equipment– Random Dot E– Stereofly– Random Dot Stereotest
Stereotests
Photos courtesy of POA
Random Dot E & Polarized Glasses
Photos courtesy of POA
Cover Test• Tests for ocular alignment disorders, strabismus, and
binocular problems• Done both at distance and near• Unilateral cover test
– Movement on Unilateral cover test = strabismus– No movement on unilateral cover test = normal
• Alternate Cover Test– Movement on Alternate cover test = Strabismus
or binocular problem, depending on severity– No movement on alternate cover test = normal
Near Point of Convergence• Tests the ability of
the eyes to converge for up-close tasks
• If the eyes cannot effectively converge for near vision tasks, then the patient has convergence insufficiency
• Equipment– Near Point fixation
stick– Tape Measure
Photos courtesy of POA
Symptoms of Children Struggling in the Classroom
• Trouble finishing written assignments• Losing their place when reading• Having a short attention span when doing
close work• Skipping words when reading• Making errors when copying from the board• Underperforming
Eye Health• The absence of anomaly or
disease• If not diagnosed or treated,
eye disease can lead to vision loss or impaired vision
• Ocular health is evaluated by external ocular examination with a biomicroscope, eye pressure evaluation, and a retina exam
The Current Lawwww.NECHILDRENSVISION.org
• Took effect in 2006-07 school year• Within 6 months of enrollment• Distance and Near Acuity• Amblyopia/Strabismus• External and Internal Eye Health
Cost of Neglecting the Problem
Increased school failure and drop out rates
Inappropriate learning disability referrals
Loss of self esteem and motivation
Increased behavior problems
Long term increase in illiteracy, joblessness and crime
Learning Preparedness
If a child cannot see, a child cannot read,
and if a child cannot read, a child cannot learn.
Good Vision = Good Education
nechildrensvision.org