Prelim- Chapter 1 Flashcards
Seeks and hold a visual image
Skeletal (convergence)
Discriminates and defines the image
Visceral ( accommodation)
Unifies, elaborates and unifies the image
Cortical (perceptual)
The only image existing in the brain is_______ which are ever in motion, fluctuating in amount and intensity
electrochemical fields
3 questions from patient
- What is my visual problem?
- What have I done to meet this problem?
- What can be done to eliminate this problem?
To answer the three questions, the optometrist must perform:
- Case study to determine the cause of the problem
- A visual skills profile to determine what the patients did to meet this problem
- Corrective procedures to eliminate the problem
- A progress report to determine the amount of visual improvement obtained by the patient and to ascertain if the problem has been eliminated
Record far point and near point, determine the kind, type and extent of the visual problem
Binocular case analysis
Purpose of case analysis
- To find the limitations of the prescriptible lens for distance and for near
- To determine whether the case can be handled by lens application alone
- To follow the changes in relationship between accommodation and convergence brought about by the new rx or the vision training program or both (progress report examination)
That which agrees with the regular and established type.
Conformance to the natural order of things.
Normal eye
Different approaches to the problem of clarifying objects or things whether they are normal or abnormal
Normative or physical viewpoint
Pathological viewpoint
Statistical viewpoint
Requires that the system must posses certain ideal values in order to be considered normal
Normative or physical viewpoint
A normal system is one which is free of pathology, a system which has no abnormal disturbances. We do not consider the degenerative processes associated with aging as being of a pathological nature.
Pathological viewpoint
is one in which the optical system needs no auxiliary lenses to obtain a sharp focus at the retinal plane. It establishes an arbitrary value of emmetropia and orthophoria as the normal conditions for efficient vision.
The normative or physical normal eye
is used to inhibit accommodation to its fullest extent, optometrists all realize that this mechanism will change because some residual accommodation is active. We never examine the visual mechanism as if it were a fixed system.
Fogging method
___________ and __________ instead of being ideal conditions for the visual mechanism, are in reality abnormal conditions which are prevalent in those individuals classifed as retarded readers. In fact, emmetropia and orthophoria, when found in an individual, seem to indicate the presence of a visual problem.
emmetropia and orthophoria,
An eye so constructed that parallel rays of light come to a focus in the retina without any effort of accommodation
Emmetropia
It is the condition of a normal eye in which the retina is situated at the posterior principal focus distance of the refracting system so that when accommodation at rest parallel rats of light is brought to focus at the retina
Emmetropia
The condition in which, the motor muscles being at rest, the visual axes are parallel to each other. This state of normal balance obtains not only when the eyes are in ordinary use, but also when they are subjected to a balance test
Orthophoria
“The ideal state of binocular balance; there exists no manifest deviation under dissociation.
Orthophoria
“When the passive position of functional rest is also the primary position; such a perfectly balanced condition of the oculo-motor system is described as orthophoria.”
Orthophoria
The phrase “normal eye” cannot be used in a definition of emmetropia because the normal eye is_____. The expression “accom-modation inactive” or “unaccommodated” cannot be used because in optometric testing procedures (non-cycloplegic) accommodation is always active.
hyperopic
The use of the “fogging technique” does not force the patient to give up all______. effort, but merely to maintain it at a minimum level which is conducive to that individual. We must define emmetropia for our purposes on a functional basis.
accommodative
______ can only refer to an individual who possesses standard acuity without the use of concave lenses and who refuses plus lenses (letters blur).
Emmetropia
Emmetropia means that there is no________________ It can be found at near as well as far.
accommodation free of association with convergence at the fixation distance.
Emmetropia is a________. It reduces one of the important psychophysiological abilities, that of changing accommodation without causing a change in convergence, to a zero range. If the stress situation continues, the organism must make some type of emergency adaptation in order to preserve the functioning unity. This usually means the appearance of minus projection.
biological mistake
The motor muscles are not at rest in the state of_____. Stimuli are constantly proceeding to these muscles. It is not an ideal condition because the efficiency of those who are orthophoric is lower than those who are exophoric.
orthophoria
Orthophoria is not a_______, as far as equating muscle strength. The muscle bulk of esophores and exophores are all the same.
balance point
is an equilibrium state in which the eyes under dissociation have the same posture as the eyes have when they are not dissociated.
Orthophoria
The presence of____ indicates that all of the latitude of protection in the convergence pattern has been used up due to a stress situation; and that any continuation of the stress situation will result in the presence of esophoria. The presence of orthophoria is undesirable, and remedial measures should be instituted to regain the buffer of exophoria as soon as possible.
orthophoria
If the eye were a static organ similar to a camera, the obvious solution to the presence of a visual problem would be to measure the power of the optical system under cycloplegia.
Static or Dynamic Eye
Ophthalmologic experience, as well as optometric experience, has shown that the great majority of patients will not tolerate such a____, but that it must be modified.
full correction
Probe bodies
Lenses
Prisms
Stages of organismic impairment
Neural
Neuromuscular
Muscular
When the person acts “as if he were a product of altered behavior, that is, he acts as it he were a myopic, astigmat, strabismic, anisometrope, etc.
The performance is characteristic, but there are no measurements of this altered performance. This is the complete functional stage. At this point, merely altering certain environmental factors will Wreadil‹ reverse this altered behavior and return it to nornial.
Neural
when we have characteristic changes in our re-{fractive measurements, but the case is still in a fluid, amenable state, highly reversible, susceptible to all corrective procedures.
neural-muscular
Considerable distortion is now present in the refractive measurements. The distortion is now embedded or structured and is no longer reversible. This distortion may be in the eye itself, in its attachments or in the central nervous system.
muscular
Highly reversible
Leaving no symptoms
Neural
Still reversible but with symptoms
Neuro-muscular
changes in supporting struc-tures, reversible if accessible, leaving definite symptoms.
Muscular
modification used is usually less ____.
plus
illustrates the effect of body posture upon vision.
Spooner
investigated the effect upon the eye of occupations involving close work.
Duke-Elder
effect of time in submarine service on vision
Schwartz and Sanberg
effect of functional modification
Edward Hartmann
higher brain centers
neopallium
Lenses are considered _____ devices
Prosthetic
______ involves a whole person
Vision
Optometry practice is interested in:
Preventing visual problems
Enhance visual skills
The visual process entails a visual mechanism which is_____ in nature and is capable of making dramatic changes in its refractive
dynamic
Standard acuity
No need for convex and concave lenses
Emmetropia
Normal eye is _____
Hyperopic
