Eyes and Vision [Name of Presenter] Doctor of Optometry.
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Transcript of Eyes and Vision [Name of Presenter] Doctor of Optometry.
The process of visionAn object in the world is seen by the
eye upside downThe brain processes the eye’s image
to create the picture of the object
BrainANDY ANDYANDY
When vision is bad...
The cornea and lens need to focus light onto the retina for clear vision
Often, the focus is not sharp...
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness)
18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Hyperopia (farsightedness)
Too little focusing power causes light to be focused “behind” the retina
Convex lenses focus light onto the retina
A significant cause of learning problems, as it often goes undetected by school or pediatrician screenings
Common cause of reading glasses
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness) 18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2% requiring referral or follow-up
Astigmatism
The cornea/lens optical system is different in the horizontal and vertical focal planes
Found in combination with farsightedness and nearsightedness
Results in blur at distance and nearCompound-grind lenses focus light onto
the retina
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness)
18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Myopia (nearsightedness)
Too much focusing power causes light to be focused “in front” of the retina
Concave lenses focus light onto the retina
Early onset occurs between 2nd and 5th grades, onset most common between grades 6th and 10th
Many control methods examined, and none work!
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness) 18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders 6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Non-strabismic binocular disorders
The “binocular” system of humans depends on vision from each eye that is equally clear and overlapped into one image instead of double
Eye aiming can be miscoordinatedMany learning difficulties can result
from the eyes not easily aiming at the same point -- the more the effort, the more the fatigue, etc.
Incidence of eye disorders, age 6 mos.
to 18 yrs.Hyperopia (farsightedness) 25%Astigmatism 23%Myopia (nearsightedness) 18%Non-strabismic binocular disorders 14%Strabismus 12%Amblyopia 7%Accommodative disorders 6%Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Strabismus “Eye turn”
Crossed eye, esotropiaWandering eye, exotropia
Double vision is uncommon because of brain adaptation called suppression
Treatments include: proper prescription, patch to equalize the individual eyes’ abilities, and surgery by age 2 for greatest chance at a functional cure
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness)
18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
AmblyopiaPhrase “lazy eye” is often used to
describe amblyopiaPermanent reduction of an eye’s best
sharpness, even with glasses, that results from the brain constantly ignoring the image of an eye that is crossed or from an eye that is significantly different in prescription than the other eye
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness)
18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Accommodative disorders
Accommodation = ability to “zoom” focus on near objects
Problems can include insufficient amount of focus, overly active focus, lock of focus, and slowly shifting focus
The muscle that controls focus can be trained to work more efficiently
Bifocals can be used for children
Incidence of eye disorders, age 6 mos.
to 18 yrs. Hyperopia (farsightedness) 25% Astigmatism 23% Myopia (nearsightedness)
18% Non-strabismic binocular disorders 14% Strabismus 12% Amblyopia 7% Accommodative disorders
6% Peripheral retinal abnormalities, 2%
requiring referral or follow-up
Peripheral retinal abnormalities
Dilated eye examinations are periodically required to evaluate parts of the inner eye that can show abnormality
Examples include retinal degenerations, retinal detachments, and retinal tumors.
Inside the numbers... 26% of US population is less than 18
years of age
31% of those 6 to 16 years old had an eye and vision examination within the past year
14% of those less than 6 years old had an eye and vision examination within the past year
Vision checkups and screenings
Many people benefit from having their eyes tested with an eye chart to see if they see properly -- called a “screening”
Vision screening is never a replacement for a comprehensive eye examination Screenings check for vision
blurriness Exams evaluate vision blurriness,
PLUS eye muscle teaming, focus ability, and eye health
Why so few eye exams?Parent reliance on vision screenings,
provided by pediatrician or school
Cost to uninsured families
Lack of good public information as to the importance of periodic eye care
Unable to pay for professional care?
NOTE: Due to differences in state, province, and region free services, add info applicable to audience, or remove slide from presentation if services are unavailable.
The Role of Vision in Learning
The eyes must see clearly, without double vision, and with accurate depth of focus control
A child must have the visual ability to learn to read prior to reading to learn
When a child cannot learn, think first of their ability to see, then of their ability to learn
Comprehensive Eye Exams
Optometrists and ophthalmologists are eye doctors who provide eye examinations
Are easy and painless!Can find the problems that relate to
poor learningHere is a “peek”...