Performing Vision screenings Flashcards
Snellen equivalent fraction
Fraction Represents the ____ (Numerator) over the ____ (denominator)
- Numerator 20 Testing distance (20ft.)
- Denominator 25 Corresponds to line on the test chart
- Distance (numerator)
- Letter Size (denominator)
____ used primarily used in reading testing
* 1M equates to standard newspaper print
M Units
Units of meausre for acuity
What type of units of measure are seen here?
10 sans serif (block style) letters
* C D H K N O R S V Z
4 numbers
* 6 8 9 5
Sloan Units
standard acuity charts
Identify what type of chart this is:
* Designed to obtain the most accurate measure in normal to near acuity range
* Stops at** 20/200 (the big E)**
* Must measure at the distance specified by the chart (ALWAYS check before using a chart)
Snellen Chart
True/False: No measurement for Vision worse than 20/200
TRUE
Standard acuity charts
Identify what type of chart this is?
ETDRS chart (Sloan)
What type of screening is this characterized by the following:
* Visual Acuity
* High contrast (distance and near)
* Color vision
* Observation of performance
Basic Vision Screening
What type of screening is this characterized by the following:
* Visual Acuity
* High contrast (intermediate and near)
* Low contrast sensitivity (near)
* Observation of performance
* SRAFVP or functional assessment
Low Vision Screening
What are some methods physicians typically use to do a subjective measure using hand as the target & this is for people with acuity below?
1. Count fingers at X number of feet
(CF at X ft.)
2. If they cant see fingers, but can see hand waving;____
3. If they cant see hand movement, but can detect light from a penlight; Light perception only (LPO)
4. If the person cant see light;____
- for acuity below 20/200
- Hand movement (HM or HMO)
- No light perception (NPO)
Low vision Acuity Test Charts provide more ____ ____ of acuity in the low vision range
Discrete assessment
How is the low vision acuity test accomplished?
By measuring acuity at Intermediate distance of 1 meter (instead of standard 10 or 20 ft.)
For the Low Vision acuity test charts; what is the extended measurable range?
20/1000 & less
What does the numerator in a Snellen fraction represent?
A) The distance between the patient and the chart
B) The size of the letters
C) The distance at which a normal eye can read the line
D) The degree of color blindness
A
Which visual acuity test uses block-style letters like C, D, H, and O?
A) Snellen Chart
B) ETDRS Chart
C) Farnsworth D15
D) Sloan Units
D
For low vision acuity, what intermediate distance is typically used?
A) 10 feet
B) 1 meter
C) 20 feet
D) 40 cm
B
Eye dominance is typically established during which stage of life?
A) Adulthood
B) Early childhood
C) Senior years
D) Adolescence
B
Which test material is used to determine eye dominance?
A) Snellen Chart
B) Ishihara Plates
C) A card with a small hole
D) Warren Text Card
C
What does OD stand for in vision shorthand?
A) Left eye
B) Right eye
C) Both eyes
D) No light perception
B
Which color vision test is commonly used to distinguish between different types of color blindness?
A) ETDRS Chart
B) Ishihara Plates
C) Sloan Units
D) Mars Chart
B
What does contrast sensitivity measure?
A) The ability to distinguish colors
B) The ability to see objects at far distances
C) The ability to see images as they degrade in contrast from their background
D) The ability to read small letters
C
Which test is designed to measure low contrast acuity?
A) Lea Low Contrast Chart
B) Snellen Chart
C) Ishihara Plates
D) Sloan Units
A
Which condition is most commonly associated with a loss of contrast sensitivity?
A) Glaucoma
B) Presbyopia
C) Cataracts
D) Age-related macular degeneration
D
What percentage contrast on the Lea Low Contrast Chart indicates difficulty seeing facial expressions and subtle drop-offs?
A) 25%
B) 10%
C) 5%
D) 1.25%
C
What does’ CC’ stand for in the physician’s shorthand for visual acuity?
A) Central Correction
B) Color Contrast
C) With correction
D) No correction needed
C
