2 Presbyopia Flashcards
What’s the “normal aging process of the eye”?
Presbyopia
What’s the function whereby converging power of the optical system of the eye is increased so that light diverging from a near source may be brought to a focus upon the retina?
Accommodation
What type of presbyopia is when you need optical correction to the BEST distance correction to achieve an acceptable near visual acuity?
Objective presbyopia
What type of presbyopia is when you need correction to the presenting distance correction to achieve acceptable near visual acuity?
Functional presbyopia
How many people worldwide have presbyopia?
One billion
Who had the theory we accept for presbyopia? He said ciliary muscle relaxes and zonular fibers at “resting” tension causes lens to contract and increasing dioptric power
Herman Von Helmholtz
In the ____ eye, the lens in under tension at the equator from the ciliary body.
In the ______ eye, ciliary muscle constricts and relaxes the tension on the equator of the lens
Relaxed
Accommodated
What type of accommodation is automatically adjustment of refractive state and up to 2.00D blur? Small scanning micro-saccades assist and is probably the LARGEST
Reflex accommodation
What type of accommodation gives you the (CA/C) ratio? Second major component
Vergence Accommodation
What type of accommodation deals with the perceived nearness of an object? Provides 80% of total near response and stimulated by perceptual cues
Proximal Accommodation
What type of accommodation is revealed in the absence of blur, disparity, and proximal inputs? Measured by removal of other three inputs (LARGE DARK ROOM).
Tonic accommodation
What are the four main contributors to affect onset of presbyopia?
Habitual task distance
Refractive error
Focusing ability
Depth of focus
Gender differences in objective presbyopia are due to what three things possibly?
Habitual task differences
Arm length
Possibly refractive error
