Dr. Dan’s Dictionary
For All You Bookworms
Accommodation: Accommodation is the ability to see clearly. Accommodation is involuntary and accommodation is fragile. In Traumatic Brain Injury and Concussion, or any insult to the brain such as high fever, anosia, or trauma, accommodation can be lost. Treatment of accommodative disorders is essential.
Amblyopia ("lazy eye"): A visual defect that affects approximately 2 or 3 out of every 100 children in the United States. Amblyopia involves lowered visual acuity (clarity) and/or poor muscle control in one eye. The result is often a loss of "3D" vision and binocular depth perception. Vision therapy can benefit this condition, but early detection is very important. For many years, it was thought that amblyopia (lazy eye) was only amenable to treatment during the "critical period." This is the period up to age seven or eight. Current research has conclusively demonstrated that effective treatment can take place at any age, but the length of the treatment period increases dramatically the longer the condition has existed prior to treatment. This condition is one of the many reasons that early childhood eye examinations are essential.
Astigmatism: Is a visual condition that occurs when the front surfaces of your eye, the cornea and lens, are slightly irregular in shape. This irregular shape prevents light from focusing properly on the back of your eye, the retina. As a result, your vision may be blurred at all distances.
Behavioral Optometrist: Behavioral optometrist spend years in post-graduate, continuing education to master the complex visual programs prescribed to prevent or eliminate visual problems and enhance visual performance. Not all optometrists practice behavioral optometry, which has as its foundation developmental and functional optometry.
Binocular Depth Perception: Binocular depth perception is a result of successful "3D" vision; the ability to visually perceive three dimensional space; the ability to visually judge relative distances between objects; a visual skill that aids accurate movement in three-dimensional space. A new book written by Dr. Susan Barry, Fixing my Gaze, speaks to the triumph of experiencing binocular depth perception.
Monocular depth perception is possible when an individual has only one seeing eye. Learning monocular depth perception clues is essential.
Binocular Vision: Vision as a result of both eyes working as a team; when both eyes work together smoothly, accurately, equally and simultaneously.
Binocular Vision Disability: A visual defect in which the two eyes fail to work together as a coordinated team resulting in a partial or total loss of binocular depth perception and stereoscopic vision. At least 12% of the population has some type of binocular vision disability. Amblyopia and strabismus are the most commonly known types of binocular vision disabilities.
Convergence: Turning the eyes toward each other to look at near objects (words at reading distance), and maintaining eye alignment comfortably and efficiently over time (attention span). Understanding convergence insufficiency is important. Convergence problems are common.
Eye-Hand Coordination Problems: Eye-hand coordination problems are noted as a lack of skill in drawing or writing. Paper work shows poor orientation on the page and the child is unable to stay within the lines when coloring. Often the child will continue to be dependent on his or her hand for inspection and exploration of toys or other objects.
Eye Movement Problems: The information obtained by the child will be reduced if eye movements are slow or clumsy, if the eyes jump, "stutter" or lose their place on instructional materials.
Eye Teaming Problems: While our eyes are supposed to work as a team so that they perform as a single and efficient unit. This teaming is not guaranteed by design. It must be acquired through use during the preschool years and not all children adequately develop this skill. It can interfere with learning, especially in the areas of comprehension and spatial relations.
Field of Vision: The physical area over which vision is possible, including motion, relative position of objects in space, contrast and movement sensitivity in side vision (reading from line to line without getting lost on the page).
Fixation: Aiming the eyes or shifting rapidly from one object to another (reading from word to word on a line).
Form Perception: organizing and recognizing visual sensations as shapes, noticing likes and differences (the difference between was and saw, that and what, 21 and 12, the letter Z and the number 0, e and o).
Glaucoma: In its most common form, glaucoma results from sustained elevated internal eye pressure and can cause severe loss of vision. Glaucoma will result in loss of peripheral (side) vision, faded images, and reduced contrast. Probably no other eye disease is more appropriately termed the “sneak thief of sight” than glaucoma. Glaucoma is the leading cause of new cases of blindness in this country. Heredity and race have an influence on glaucoma. OPEN-ANGLE GLAUCOMA, the most common variety, rarely causes any symptoms and often goes unnoticed until the peripheral vision loss is severe and permanent. In advanced stages, impaired side and central vision with decreased sight acuity are noted. Another type of glaucoma called LOW or NORMAL TENSION GLAUCOMA is prevalent when normal-to-low pressure is present. In this case, as well as chronic open angle cases, the eye cannot maintain adequate blood circulation, which can result in damage to the optic nerve, loss of peripheral vision, and reduced sight. Glaucoma is a complex condition requiring lifelong extensive care and monitoring.
Hemianopia: Defective vision or blindness in half of the visual field. Patients suffering neurological insult frequently have visual field loss. The visual field loss is often times to the right or left, involving one half of ones vision (i.e. a hemifield). When the visual hemifield loss, because of the neurological cause, is equal in the right and left eyes, this is known as a homonymous hemianopsia. The visual field loss can also be constricted, or within one small area of the visual space. It may be a complete loss of the vision in the effected field, or it may be a relative loss of sensitivity. Visual field loss, or a loss of "sight" in a portion of the visual field, and "visuospatial neglect", also known as visual hemi-inattention, may occur separately or in conjunction with each other.
Hyperopia: Farsightedness, or hyperopia, as it is medically termed, is a vision condition in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eyeball is too short of the cornea has too little curvature, so light entering your eye us not focused correctly on the retina.
Myopia: Nearsightedness, or myopia, as it is medically termed, is an epidemic visual condition in which near objects are seen clearly, but distant objects do not come into proper focus. Nearsightedness occurs if your eyeball is too long or the cornea has too much curvature, so the light entering your eye is not focused correctly on the retina.
Neglect: Visuospatial neglect in its most pure form results in a clinical picture similar to visual field loss. However, neglect is different from a visual field loss, in that the brain areas that support sight are intact. The patient with "visuospatial neglect" has intact sight, but has suffered a perceptual loss of vision, and cannot "see" the objects in the neglected hemifield, because they cannot bring them to conscious perception due to an attentional deficit. Like visual field loss, visuospatial neglect may manifest as a complete loss of visual perception on the affected side, or as a relative loss where less is perceived in the neglected field, particularly when there are competing stimuli in the opposite hemifield. –
When "visual neglect" is present with hemianopia, the brain areas supporting sight are not intact. Visuospatial neglect with hemianopia can cause severe lifelong impairments without treatment. Research and lectures regarding driving with vision loss lists "visual neglect" as frequently preventing a return to driving. However, new research measures support the possibility of functional improvement and independence of driving with new prism and treatment methods breaking through "visual neglect".
Ocular Motor Tracking: Ocular motor tracking is the visual skill of attention, focus, and visual sequential abilities. These are directionally from left to right for reading English, and right to left for reading Hebrew. Other languages require vertical ocular motor tracking. Ocular movement treatment includes innovative patent-pending prisms and power sometimes improving abilities within seconds.
Presbyopia: Is a vision condition in which they crystalline lens of your eye loses its flexibility, which makes it difficult for you to focus on close objects. Presbyopia may seem to occur suddenly, but the actual loss of flexibility takes place over a number of years. Ocular movement treatments include innovative patent-pending prisms and power that are creating improved abilities in seconds. During Presbyopia, binocular vision frequently breaks down.
Refractive Status Problems: Nearsightedness (myopia), farsightedness (hyperopia), some cases of astigmatism and focusing problems interfere with a child's comprehension processes and classroom participation. These problems can be developing even though the child may see 20/20 on a Snellen Chart. They need prompt attention by a behavioral Optometrist who treats both vision and sight. There are new preventive methods for vision changes of progressive Myopia, which has become epidemic.
Strabismus ("crossed eye," "wall eye," "wandering eye," esotropia, exotropia, hyperphoria): Affects approximately 4 out of every 100 children in the United States. It is a visual defect in which the two eyes point in different directions. One eye may turn either in, out, up, or down while the other eye aims straight ahead. Due to this condition, both eyes do not always aim simultaneously at the same object. This results in a partial or total loss of stereo vision and binocular depth perception. The eye turning may be visible at all times or may come and go. In some cases, the eye misalignments are not obvious to the untrained observer. Strabismus is treatable – Preparing individuals for binocular vision from infancy on using prism and therapy will help avoid multiple surgeries.
Stereo Vision: (stereopsis or stereoscopic vision): A byproduct of good binocular vision; vision wherein the separate images from two eyes are successfully combined into one three-dimensional image in the brain.
Syntonics: Syntonics or optometric phototherapy, is the branch of ocular science dealing with the application of selected light frequencies through the eyes. It has been used clinically for over 70 years in the field of optometry with continued success in the treatment of visual dysfunctions, including strabismus (eye turns), amblyopia (lazy eye), focusing and convergence problems, learning disorders, and the after-effects of stress and trauma. In recent years, Syntonics has been shown to be helpful in the treatment of brain injuries and emotional disorders. In Syntonics optometry, the patient is exposed to one or more colors of light for a fixed period of time. This is done in a darkened room, with colors generated by a machine known as a syntonizer. In a typical session, a patient might absorb one color for 10 minutes, then another for an additional 20 minutes. Treatment typically could involve between three and five sessions a week, for a period of four to eight weeks. In most cases, syntonics is used in conjunction with other therapeutic procedures.
Tracking: Tracking is the ability of the eyes to keep attention and focus on moving objects.
Vision: The act of perceiving and interpreting visual information with the eyes, mind, and body.
Vision Therapy: A medical treatment designed to improve visual skills such as:
- Eye Teaming
- Binocular Vision and Depth Perception
- Ocular Motor Tracking
- Acuity (clarity of sight)
- "Hand-Eye" or "Vision-Body" coordination
- Visual Perception
Vision therapy can involve a variety of procedures to correct neurophysiological or neurosensory visual dysfunctions.
Visual Form Perception Problems: Form perception problems usually are a result of difficulties in the discrimination of visible likenesses and differences. There is confusion with similarities, inattention to slight differences, reversals of letter forms, and reversals in reading. This produces difficulties in spelling, writing, and reading comprehension.