Aberrometer A device that can identify common and more
obscure vision errors by measuring the way light waves
travel through the eye's optical system.
Ablation: Surgical removal of the eye.
Achromatopsia: a rare hereditary vision disorder lacking
normal cone vision therefore, persons with achromatopsia
are either totally colorblind or almost totally colorblind, and
they have poor visual acuity.
Accommodation: 1. (biology) Eye's ability to automatically
change focus from seeing at one distance to seeing at
2. (Education)  are services or supports used to
enable a student to fully access the subject matter and
instruction.  Examples include books on tape, content
enhancements, and allowing additional time to take a test.
Accommodation disorder: The eye's inability to
automatically change focus from seeing at a distance to
seeing at near.
Albinism: refers to a group of inherited conditions. People
with albinism have little or no pigment in their eyes, skin,
or hair.
Amblyopia: also called "lazy eye" it is when the vision in
one of the eyes is reduced because the eye and the brain are
not working together properly. The eye itself looks normal,
but it is not being used normally because the brain is
favoring the other eye.
Aniridia: Partial or complete absence of the iris of the eye.
This rare condition, usually present at birth, results in
impaired vision and sensitivity to light.
Anopthalmia: condition in which one or both eyes do not
form during pregnancy. When both eyes are affected,
blindness results.

Aphakia: Absence of the lens of the eye. Aphakia is usually
associated with the surgical removal of a cataract but may
also result from a wound or other cause.
Assistive Technology is technology designed to be used in
an assistive technology device or assistive technology
service. An assistive technology device is any item, piece of
equipment, that is used to increase, maintain, or improve
functional capabilities of individuals with disabilities.
Examples include: Braille readers, motorized wheelchairs,
and specialized keyboards.
Astigmatism: the result of an inability of the cornea to
properly focus an i
mage onto the retina resulting in a
blurred image.

Best's Disease  Rare, inherited condition that affects
the macula, the area in the middle of the retina, and can
cause blurred or distorted vision or a loss of central vision.
Best's Disease, also known as Vitelliform Macular
Dystrophy, may affect both eyes
Blepharitis:  an inflammation of the eyelid margin that may
have several causes and can result in mild to severe
discomfort and irritation as well as possibly blurred vision.
Blindness: visual acuity of not greater than 20/200 in the
better eye with correction or a field not subtending an angle
greater than 20 degrees.

Cataracts: a clouding of the eye’s lens that diminishes vision.
Charles Bonnet syndrome: Visual disturbances usually
occurring in people who have experienced visual impairment
or sight loss later in life, as through macular degeneration.
People with Charles Bonnet syndrome may see a wide range
of images, from simple patterns to people, animals, and
buildings. The visual disturbances associated with this
syndrome are not signs of mental illness, and people realize
that the images they are seeing are not real.
Chlamydial Inclusion Conjunctivitis is an infection of the
conjunctiva of the eye that is caused by the sexually
transmitted disease called Chlamydia.
Choroideremia: Rare disorder that causes progressive loss
of the choroid, an important layer under the retina that is
responsible for some of its blood supply.
Ciliary body: is a ring of tissue with muscle fibers that
change the size of the pupil and the shape of the lens. It is
found behind the iris.
Coloboma: of the iris: is a hole or defect of the iris of the
eye. Most colobomas are present since birth (congenital).
Color blindness:  vision problem in which a person has
difficulty distinguishing certain colors—most commonly red
and green, but sometimes blue and green or blue and yellow.
Color blindness is not really a form of blindness, but rather a
deficiency in color perception.
Computer Vision Syndrome: A condition where after
working on a computer the user experiences headaches,
eyestrain, blurred vision, fatigue, or dry, burning eyes
Cone-rod dystrophy: Inherited disease that, over time,
causes deterioration of the specialized light-sensitive cells
of the retina. People with cone-rod dystrophy typically
experience decreased sharpness of vision followed by a loss
of peripheral vision and color perception. The most common
form of cone-rod dystrophy is retinitis pigmentosa.
Congenital eye defects: Any of various conditions present
at birth that affect the eyes or vision.
Conjunctivitis: is redness & inflammation of the membranes
covering the whites of the eyes and on the inner part of the
Corneal disease: Disease or disorder that affects the
cornea, the clear, curved surface that covers the front of the
eye. The effects of corneal disease vary. Some corneal
conditions cause few, if any, vision problems.
Corneal ulcer:  an open sore on the cornea, the clear
structure overlying the iris (which is the colored part of
your eye).  A
Cortical visual impairment: Visual impairment caused by
damage to those parts of the brain related to vision.
Although the eye is normal, the brain cannot properly
process the information it receives. The degree of vision
loss may be mild or severe and can vary greatly, even from
day to day.

Deaf-Blindness: simultaneous hearing and visual
impairments, the combination of which causes such
severe communication and other developmental and
educational needs that they cannot be accommodated
in special education programs solely
for children with
deafness or children with blindness.
DeMorsier's Syndrome: Rare disorder, present at
birth, in which the optic nerve is underdeveloped, the
pituitary gland does not function properly, and often a
portion of brain tissue is not formed.

Developmental Delay occurs when a child's development
progresses at a slower rate than most children. This is
often seen as a delayed achievement of one or more of
a child's milestones. A developmental delay can affect
a child's physical development, cognitive development,
communication development, social or emotional
development, or adaptive development.
Diabetes Eye Complications
Diabetic retinopathy  Eye condition that results from
the damaging effect of diabetes on the circulatory
system of the retina.
Drusen are very small yellow or white spots that
appear in Bruch's membrane (one of the layers of the
retina in the eye).
Dry eye syndrome: Persistent dryness of the eyes
resulting from too little production of tears or too
rapid evaporation of tears. People with dry eye
syndrome may experience such symptoms as itching,
burning, or stinging eyes
Extended School Year(ESY) refers to the special education
and related services which meet the state standards that a
student with disabilities receives beyond the school year as
stipulated in the IEP. These services are provided at no
charge to the family or student.
Eye muscle repair is surgery to correct eye muscle problems
that cause crossed eyes. The medical term for crossed eyes
is strabismus.
Eye tumor:
FAPE stands for "free appropriate public education." This
right is guaranteed to students with disabilities by IDEA.
The provision states that special education and related
services, in accordance with the state's standards, are
provided free of charge under public supervision and
direction in compliance with the student's IEP. It includes
preschool, elementary school, or secondary school education.
Farsightedness Also called hyperopia. To farsighted people,
near objects are blurry, but far objects are in focus.
Floaters: floaters are those tiny spots and specks that drift
aimlessly around in your field of vision. While annoying,
ordinary eye floaters and spots are very common and usually
aren't cause for alarm.
Functional Blindness: the absence of any usable vision. Only
about 1 in 10 visually impaired people are functionally blind.
Most have some usable vision.
Fungal keratitis eye infection:

Giant papillary conjunctivitis is an allergic reaction resulting
in inflammation of the palpebral conjunctiva (thin membrane on
the underside of the eyelids).  Commonly called GPC by eye
Glaucoma:  to a group of eye conditions that lead to damage to
the optic nerve, the nerve that carries visual information from
the eye to the brain, due to increased pressure in the eye.
Geographic atrophy:
Graves' ophthalmology:
Hemianopia: Blindness affecting half of the field of
vision. Hemianopia, also known as hemianopsia, may be
caused by various medical conditions, but usually results
from a stroke or brain injury.
Higher-order aberration:
Histiocytosis Abnormal proliferation of
(immune system cells). Common symptoms include bone
tumors and skin rashes. If histiocytosis affects the
eyes, it causes bulging.

Read more: http://www.allaboutvision.
Horner's syndrome:
Hyperopia: farsightedness.
Hypoplasia: underdevelopment of an organ or tissue. When
you child's eye report reads that there is "optic nerve
hypoplasia" it means that nerve is not developed.
Hypotony: low eye pressure.

Individuals with Disabilities Education Act (IDEA) was
first enacted in 1975 as the Education for all
Handicapped Children Act. It is a comprehensive law that
governs the education of students with disabilities. The
current version of the law was amended in 2004
(referred to as IDEA '04 or PL 108-446). For more
information about the IDEA, go to the U. S. Department
of Education's IDEA web site at This
new site was created to provide a one-stop shop for
resources related to IDEA and its implementing

Individualized Education Program (IEP) is a legal document
designed by a team of educators, specialists, and the
child's parent(s)/guardian(s) that outlines the child's
learning/behavioral goals and objectives. This document
must be updated at least every 12 months; however, an
IEP team meeting can be called by any member of the
team at anytime. The IEP includes a description of the
child's present level of educational performance and
identifies annual goals and objectives along with methods
for assessing progress toward goals and objectives. In
addition, the IEP includes any necessary supports,
accommodations, adaptations, and/or related services.

Inclusion: when students with disabilities are included in
the general education classroom/program to the extent
possible. Any support services the student needs will be
provided in this setting.
Intraocular (Eye) Melanoma: a disease in which malignant
(cancer) cells form in the tissues of the eye.
Intraocular lens:
Intraocular pressure (IOP):

Keratoconus:  is a thinning disorder of the cornea that
causes distortion and reduced vision.
Keratoconjunctivitis sicca: Dry eye syndrome.
Laser Eye Surgery: Laser eye surgery reshapes the
cornea, the clear front part of the eye. This changes its
focusing power. For many people, laser eye surgery can
correct their vision so they no longer need glasses or
contact lenses.
Least Restrictive Environment (LRE) refers to the
concept that children with disabilities should be educated
to the maximum extent possible with children who are not
disabled while meeting all their learning needs and
physical requirements. The type of setting is stipulated
in a child's IEP.
Laurence-Moon-Bardet-Biedl Syndrome: Rare, inherited
disorder affecting many parts of the body. People with
this condition have retinitis pigmentosa accompanied by
mental retardation, paralysis of the legs, and various
other symptoms. [I've had at least 3 students with this
condition. Also see Laurence Biedl, Laurence Biedl Moon
Leber's congenital amaurosis: Inherited condition,
probably caused by degeneration of the retina, in which
an infant is born blind or develops severe vision loss soon
after birth. Children with Leber's congenital amaurosis
typically also have nystagmus, and some also have mental
retardation and hearing disorders.

Legal Blindness: •Visual acuity of 20/200 or worse in the
better eye with corrective lenses (20/200 means that a
person at 20 feet from an eye chart can see what a
person with normal vision can see at 200 feet);

Definitions M-Z
Ms. Kathy is still replacing terms
and definitions to this page. Thank
you for your patience!