COA EXAM STUDY (JCAHPO) TEST QUESTIONS WITH ACCURATE SOLUTIONS (GRADED
A+)
Astigmatism
the condition in which rays of light are not refracted equally in all directions
2 types of Astigmatism
- Regular Astigmatism
- Irregular Astigmatism
Regular Astigmatism
Refractive condition that is corrected by cylinders
Types of regular astigmatism
-Simple Astigmatism
-Compound Astigmatism
-Mixed Astigmatism
At birth the cornea's shape?
Perfect Shape
,By age 4 the cornea's shape?
loses its spherical qualities
With the rule astigmatism?
The horizontal axis of the cornea becomes more steeply inclined so that rays of light are
refracted more acutely than those rays being refracted along the vertical axis of the cornea
Cornea can be divided into five distinct portions?
1. Epithelium
2. Bowman's Layer
3. The Stroma
4. Descemet's Membrane
5. Endothelium
The vitreous occupies ________ of the globes volume
2/3rds
The rods function best in ?
Dim Light
The cones function best in______ ?
,day light
Cones allow what type of vision?
Color Vision
Damage of the rods result in?
night-blindness
The optic nerve consists of how many axons?
1 million
Heterophoria?
the position the eyes assume when fusion is disrupted
Esophoria
drifting in of the eye when under cover
Exophoria
drifting out of eye when under cover
, Hyperphoria
drifting up or down of the eye under cover
Lenticular Astigmatism
Astigmatism resulting from unequal bending of light by the crystalline lens.
Astigmatism with the rule
The vertical corneal meridian has the steepest curvature
Astigmatism against the rule
The horizontal meridian has the steepest curvature
Average K's reading is?
42-48 Diopters
Rigid lenses use what material?
silicone and Flurocarbon
What material is used in contact lens polymerization?
A+)
Astigmatism
the condition in which rays of light are not refracted equally in all directions
2 types of Astigmatism
- Regular Astigmatism
- Irregular Astigmatism
Regular Astigmatism
Refractive condition that is corrected by cylinders
Types of regular astigmatism
-Simple Astigmatism
-Compound Astigmatism
-Mixed Astigmatism
At birth the cornea's shape?
Perfect Shape
,By age 4 the cornea's shape?
loses its spherical qualities
With the rule astigmatism?
The horizontal axis of the cornea becomes more steeply inclined so that rays of light are
refracted more acutely than those rays being refracted along the vertical axis of the cornea
Cornea can be divided into five distinct portions?
1. Epithelium
2. Bowman's Layer
3. The Stroma
4. Descemet's Membrane
5. Endothelium
The vitreous occupies ________ of the globes volume
2/3rds
The rods function best in ?
Dim Light
The cones function best in______ ?
,day light
Cones allow what type of vision?
Color Vision
Damage of the rods result in?
night-blindness
The optic nerve consists of how many axons?
1 million
Heterophoria?
the position the eyes assume when fusion is disrupted
Esophoria
drifting in of the eye when under cover
Exophoria
drifting out of eye when under cover
, Hyperphoria
drifting up or down of the eye under cover
Lenticular Astigmatism
Astigmatism resulting from unequal bending of light by the crystalline lens.
Astigmatism with the rule
The vertical corneal meridian has the steepest curvature
Astigmatism against the rule
The horizontal meridian has the steepest curvature
Average K's reading is?
42-48 Diopters
Rigid lenses use what material?
silicone and Flurocarbon
What material is used in contact lens polymerization?
