20/20
20/20 vision: Expression for normal visual acuity measured at a distance of 20 feet. 20/20 vision means you can see clearly at 20 feet what should normally be seen at 20 feet. 20/80 vision means that you can see at 20 feet what a person with normal vision can see at 80 feet.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”a”][vc_column][vc_column_text el_class=”glossary-answer”]
A
Acuity: The clarity or sharpness of vision.
Amblyopia: Amblyopia is poor vision in an eye that otherwise appears normal. It is sometimes called “lazy eye.” Amblyopia occurs when the brain does not recognize the sight from that eye. Eventually, the brain stops using the weaker eye, causing poor vision or even blindness in that eye.
Amplitude: Size of the evoked potential generated by the brain (also known as magnitude).
Astigmatism: A defect in a curvature of the cornea or lens of the eye. As a result, a ray of light is not sharply focused on the retina but is spread irregularly.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”c”][vc_column][vc_column_text el_class=”glossary-answer”]
C
Cornea: Transparent anterior portion of the outer covering of the eye; it covers the lens and iris and is continuous with the sclera.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”d”][vc_column][vc_column_text el_class=”glossary-answer”]
D
Diabetic Retinopathy: Diabetic retinopathy is damage to the eye’s retina that occurs with long-term diabetes. See FAQs for more information on retinopathy and diabetes.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”e”][vc_column][vc_column_text el_class=”glossary-answer”]
E
Electronic Response: A signal that is produced in direct correlation to the stimulus.
Eye care specialist: Generally an optometrist or ophthalmologist who performs eye exam tests to help diagnose and treat disorders relating to the eye and vision.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”g”][vc_column][vc_column_text el_class=”glossary-answer”]
G
Glaucoma: Glaucoma refers to a group of eye conditions that lead to damage to the optic nerve. This nerve carries visual information from the eye to the brain. In most cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP). See FAQs for symptoms for glaucoma.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”h”][vc_column][vc_column_text el_class=”glossary-answer”]
H
Hydroxychloroquine: Hydroxychloroquine (also known as Plaquenil) is a drug first used to prevent and treat malaria. Today, it is most commonly prescribed for dermatologic and rheumatologic inflammatory conditions, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Long-term use of the drug can lead to retinal toxicity and vision loss, which may be irreversible and may continue to progress even after stopping the drug. This is often referred to as “Plaquenil toxicity” or “Hydroxychloroquine-Induced Toxicity.”
Retinal toxicity is of serious ophthalmologic concern because it is not treatable, but if caught early enough, may prevent further vision loss. “The goal of screening for retinopathy is not to stop valuable drugs at the first borderline abnormality, but to recognize definitive signs of toxicity at an early enough stage to prevent a loss of visual acuity.” (American Academy of Ophthalmology).
Hyperopia: Farsightedness; a person can see distant objects more clearly than close objects. A refractive error in which the eyeball is too short from front to back or the refractive power of the eye is too weak, so that parallel rays of light brought to a focus behind the retina.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”i”][vc_column][vc_column_text el_class=”glossary-answer”]
I
Impulse: The electrical discharge that travels along a nerve fiber.
Intraocular Pressure (IOP): is a measurement of the fluid pressure inside the eye.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”l”][vc_column][vc_column_text el_class=”glossary-answer”]
L
Latency: The time that elapses between a stimulus and the response to it.
Lens: Part of the eye that is transparent and is used to converge or diverge transmitted light and to form images.
Lateral Geniculate Nucleas (LGN): Distributes the electric signal to the visual cortex.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”m”][vc_column][vc_column_text el_class=”glossary-answer”]
M
Magnitude: Size of the evoked potential generated by the brain (also known as amplitude).
Misalignment: A muscle imbalance where the two eyes are not aligned either horizontally, vertically or both. See strabismus.
Monocular blindness: Blindness in one eye.
Multifocal Electroretinography (mfERG): According to the International Society for Clinical Electrophysiology of Vision (ISCEV), the clinical multifocal electroretinogram (mfERG) is an electrophysiological test of local retinal function. With this technique, many local ERG responses are recorded quasi-simultaneously from the cone-driven retina under light-adapted conditions.
Multiple Sclerosis (MS): Multiple sclerosis is an autoimmune disease that affects the central nervous system, specifically the brain and spinal cord.
Myopia: Nearsightedness; a person can see near objects clearly while distant objects appeared blurred. A refractive error in which the eyeball is too long or the refractive power to strong, so that parallel rays of light are focused in front of the retina.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”n”][vc_column][vc_column_text el_class=”glossary-answer”]
N
Non-Invasive: For the purposes of an eye exam this means no drops or touching the eye in any way.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”o”][vc_column][vc_column_text el_class=”glossary-answer”]
O
Ophthalmologist: A medical doctor specializing in the treatment of diseases of the eye and vision. See FAQs for more information on ophthalmologist versus optometrist.
Optometrist: An eye specialist trained to diagnose, treat and monitor eye and vision care, eye diseases and related conditions, and prescribe eyeglasses, contact lenses, and medications to treat eye disorders.
Optic Nerve: Delivers the electrical signal from the retina to the Lateral Geniculate Nucleus.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”p”][vc_column][vc_column_text el_class=”glossary-answer”]
P
Phase: Latency of the signal from the eye to the visual cortex of the brain.
Plaquenil: Hydroxychloroquine (also known as Plaquenil) is a drug first used to prevent and treat malaria. Today, it is most commonly prescribed for dermatologic and rheumatologic inflammatory conditions, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Long-term use of the drug can lead to retinal toxicity and vision loss, which may be irreversible and may continue to progress even after stopping the drug. This is often referred to as “Plaquenil toxicity” or “Hydroxychloroquine-Induced Toxicity.”
Retinal toxicity is of serious ophthalmologic concern because it is not treatable, but if caught early enough, may prevent further vision loss. “The goal of screening for retinopathy is not to stop valuable drugs at the first borderline abnormality, but to recognize definitive signs of toxicity at an early enough stage to prevent a loss of visual acuity.” (American Academy of Ophthalmology).
Pre-Verbal: Before talking.
Pre-Literate: Before reading.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”r”][vc_column][vc_column_text el_class=”glossary-answer”]
R
Refractive Error: A defect in the eye that prevents light rays from being brought to a sharp focus exactly on the retina. The amount of myopia, hyperopia or astigmatism presents in the eye.
Retina: The sensory membrane that lines the eye, receives the image formed by the lens, is the immediate instrument of vision, and is connected with the brain by optic nerve.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”s”][vc_column][vc_column_text el_class=”glossary-answer”]
S
Spatial Frequency: Grading frequency that is equivalent to the Snellen eye chart.
Snellen Acuity Chart: Display consisting of a printed card with letters and numbers in lines decreasing in size; eye exam test used to test visual acuity.
Strabismus: The two eyes are not directed at the same point; misalignment of the eye.
Sweeps: Predetermined set of patterns.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”t”][vc_column][vc_column_text el_class=”glossary-answer”]
T
Traumatic Brain Injury (TBI): a form of acquired injury to brain, occurs when a sudden trauma causes damage to the brain. See FAQs section for symptoms of brain injury.
[/vc_column_text][/vc_column][/vc_row][vc_row el_id=”v” css=”.vc_custom_1487704453199{padding-bottom: 15px !important;}”][vc_column][vc_column_text el_class=”glossary-answer”]
V
Visual Cortex: The cortical area that receives information from the lateral geniculate body of the thalamus.
Visual Evoked Potential (VEP): An electrical signal generated in response to a known visual stimulus. See FAQs for more information related to vision care and the eye test related to VEP.
[/vc_column_text][/vc_column][/vc_row] 