Astigmatism and Presbyopia Flashcards
“Presbys” means what?
Old
Ciliary muscle is also known as what muscle?
Autofocus
Virtually no accommodation ability remains
Absolute Presbyopia
The condition in which near vision difficulties result from an apparent decrease in the AA in dim light.
Nocturnal Presbyopia
The inability of the human eye to focus on objects up close that results with aging.
Presbyopia
Condition which can still be overcome by a hard or forced ciliary effort.
Facultative Presbyopia
The earliest stage at which symptoms or clinical findings document the near vision effects of the condition.M
Incipient Presbyopia
It is a corneal inlay treatment for presbyopia, is 3-mm in diameter and about 15 microns thick.
Flexivue Microlens
The Presbylens may not give a better overall range of vision than standard mono vision. True or False?
False
May give
What age does Presbyopia usually starts?
40-50
Presbyopia is also known as?
Short arm syndrome
“Ops” means what?
Eye
Theory in which the amount of ciliary muscle contraction required to produce a unit change in acc. remains constant with age.
H-H-G Theory or Helmholtz-Hess-Gullstrand Theory
Give at least two cause of sclerosis.
- Nutrtional Changes
- Action of UV rays
- Exposure to intense infrared radiation
Inability to see far distances distinctly is one of Presbyopia’s symptoms. True or False?
False
Near
The crystalline lens has an unequal curvature on the surface or in its layers
Lenticular Astigmatism
One of the principal meridians is focused on the retina and the other is not focused on the retina
Simple Astigmatism
When both principal meridians are focused either in front or behind the retina
Compound Astigmatism
Infants are born with ATR astigmatism. True or False?
True
Refractive condition in which a variation of power exists in different meridians of the eye.
Astigmatism
The major source of astigmatism is held to be the _____?
Anterior surface of the cornea
What surface may exhibit some irregularity?
Fundus
Something different from another of the same type.
Variation
The basic correction for astigmatism consists of what power?
Cylindrical
How is astigmatism diagnosed?
- Keratometry
- Visual acuity
- Refraction
Different types of astigmatism are classified based on the length of the cornea. True or False?
False (shape)
The first accurate description of astigmatism as such is credited to?
Thomas Young
He was the first one to produce a distance test charts for Astigmatism.
John Green
The cornea has unequal curvature on the anterior surface
Corneal astigmatism
When one of the principal meridians is focused behind the retina and the other is focused on the retina
Simple Hyperopic astigmatism
