Accommodation Vocab Flashcards
Punctum Remotum (PR)
The far point of clear vision with accommodation relaxed. Two conjugate points, one in space, one on the retina, so that when light originates from the point in space, it focuses on the retina with accommodation relaxed.
Emmetropia conjugate points and PR
Infinity and the retina. The PR is infinity. PR for all emmetropes is the same.
Myopia conjugate points and PR
inside infinity and the retina. The PR is inside infinity. PR for all myopes are not the same.
Hyperopia conjugate points and PR
Beyond infinity (has a negative value). The PR is beyond infinity. All hyperopes do not have the same PR
Punctum proximum PP
The nearest and closes point of clear vision. This is determined by performing Donder’s amplitude of accommodation measurement.
Amplitude of accommodation
The dioptric difference between the accommodative PR and the PP.
Type of accommodation: Tonic accommodation
Resting state of accommodation. The portion of accommodation present in absence of a stimulus
Type of accommodation: Psychic accommodation
Stimulation of accommodation caused simply by the nearness of a target. Ex: phoroper in front of face may make pt accommodate more at a distance.
Type of accommodation: Reflex accommodation
What happens when stimulus falls behind retina. Automatic, non-volitional (without volunteering) change in accommodation as a response to blur.
Type of accommodation: Abberational accommodation
Range in accommodation due to chromatic aberration- change in accommodation can vary, depending on which color is focused on the retina.
Ex: red/green filter= chromatic. Helps cut down on glare, and helps the pt not fall asleep. “focus on the __ and grace at the ___”
Four Type of accommodations
Tonic, psychic, reflex, abberational
7 anomalies in accommodation
Excessive, spasm, tonic spasm, clonic spasm, insufficient, inertia, paralysis
Anomaly in accommodation: Excessive accommodation
A constant parasympathetic (visceral, rest and digest) stimulation of accommodation, when there is no need for accommodation. Pt may present as a myope.
Anomaly in accommodation: Spasm of accommodation
The ciliary muscle is in a state of spasm.
Anomaly in accommodation: Tonic spasm
Type of spasm that is prolonged and uniform. Example: reading at near for a long period of time and then looking into the distance. Distance vision will be blurred since accommodation is still active- artificial myope at this time until it relaxes.
Anomaly in accommodation: Clonic spasm
Type of spasm. Alternate, intermittent spasm of accommodation. Can be observed during ret- tell pt to focus on something else (wiggle toes) and that will relax their accommodation (distance vision)
Anomaly in accommodation: Insufficient accommodation
Accommodative amplitude below the limits of age level expected. Usually adults or premature presbyopes will complain of this. Need to hold papers further away to see.
Anomaly in accommodation: Inertia of accommodation
When a change in focus is needed by a patient, there is a delay in the accommodative system, making a change necessary for clear vision.
Not that they can’t, it just takes them longer to focus from distance too near. Delayed. “Blurry for a second or two.”
Anomaly in accommodation: Paralysis of accommodation
Accommodation is non-functional due to drugs, infections, trauma, or congenital reasons. The patient has near point blur and a dilated pupil.
Ex: cyclo/topical drug. Or ciliary body infected or trauma to it.
Cyclopleigic
A drug, applied topically to the eye, which causes a paralysis of accommodation and secondary pupil dilation.
Isometropia
The condition in which the refractive condition is the same for the two eyes. Ex: -2.00 DS OU
Anisometropia (umbrella term)
The condition in which the refractive condition is not the same for the two eyes.
- 1.00 OD
- 2.00 OS
Antimetropia
A specific type of anisometropia, where one eye is myopic and the other eye is hyperopic.
Ametropia
A refractive condition the than emmetropia
Fogging
in refraction, the use of excessive plus plus power to place the retinal image in front of the retina, to prevent the patient from accommodating,
How do mono vision cis affect depth perception
No binocularity, only monocularly. Tell pt’s not to drive in them until they feel comfortable.
