Visual Acuity Assessment Quiz

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Questions and Answers

What is the recommended text size and contrast for optimal reading performance?

3 times larger and 30 times greater contrast than threshold
6 times larger and 30 times greater contrast than threshold (correct)
10 times larger and 30 times greater contrast than threshold
3 times larger and 10 times greater contrast than threshold

What is the recommended text size and contrast for a patient with low vision aiming to regain reading fluency?

10 times larger and 30 times greater contrast than threshold
6 times larger and 30 times greater contrast than threshold
3 times larger and 10 times greater contrast than threshold (correct)
3 times larger and 30 times greater contrast than threshold

What is the recommended method for maximizing contrast reserves in patients with low vision?

Using specialist lighting or electronic vision enhancement devices (correct)
Adjusting the working distance of the patient
Using conventional near adds
Using larger print sizes

How does the reading speed curve change in patients with low vision compared to normally sighted individuals?

It moves to the right and may become less steep (A) Signup and view all the answers

What is the primary reason for the decline in reading speed with decreasing print size in normally sighted individuals?

Reduced visual acuity (B) Signup and view all the answers

What might cause the right-hand side of the reading speed curve to rise when using a low vision aid to read large print?

Reduced field of view (D) Signup and view all the answers

What is a significant limitation that prevents the reading speed curve from reaching optimal levels even with the use of low vision aids?

Limited field size and handling limitations (A) Signup and view all the answers

What are the three historical forms in which near acuities are specified?

Jaeger, N Point, and Snellen Equivalent (A) Signup and view all the answers

What is the recommended classification for individuals with visual acuity less than 0.5/60 (LogMAR 2.0) who can detect movement?

Hand Movements (HM) (D) Signup and view all the answers

Why is the use of "Counting Fingers (CF)" as an indicator of poor vision discouraged?

It does not provide a reliable measure of visual acuity. (C) Signup and view all the answers

What percentage of the visually impaired population is estimated to have "No Perception of Light (NPL)" vision?

Less than 5% (A) Signup and view all the answers

What is the primary reason for emphasizing the importance of contrast sensitivity in routine optometric practice?

It is more relevant to everyday visual tasks. (D) Signup and view all the answers

What is the relationship between contrast sensitivity and contrast detection threshold?

They are inversely proportional. (A) Signup and view all the answers

How is the contrast sensitivity of a patient determined using sine wave gratings?

The score is the logarithm of the contrast sensitivity of the last group of three letters, of which at least two were read correctly. (C) Signup and view all the answers

Which of these everyday visual tasks requires the highest contrast threshold for 'fluent reading'?

Using a computer screen (D) Signup and view all the answers

Why is it important to record test distance and chart type alongside every visual acuity measurement?

To ensure accurate data analysis and comparison between different practitioners. (C) Signup and view all the answers

What is the primary purpose of the Brightness Acuity Tester (BAT)?

To assess the patient's ability to see in low-contrast conditions (A) Signup and view all the answers

Which of the following is NOT a common setting used in the Brightness Acuity Tester (BAT)?

Dimly lit room with artificial light (A) Signup and view all the answers

Which of the following is NOT a benefit of using LogMAR scales for acuity charts?

LogMAR scales allow for the use of letters of varying sizes. (A) Signup and view all the answers

What is the main advantage of expressing visual acuity in the Snellen fraction notation (d/D)?

It eliminates the possibility of confusion with LogMAR results. (B) Signup and view all the answers

Which of the following is NOT a factor that can be adjusted in a low vision assessment using a digital test chart?

Letter shape fidelity. (D) Signup and view all the answers

What is the main limitation of traditional test charts in terms of digital presentation?

They result in limited letter shape fidelity due to pixellation. (B) Signup and view all the answers

What does the term "LogMAR" stand for?

Logarithmic Minimum Angle of Resolution (C) Signup and view all the answers

What is the primary purpose of visual field assessment within a low vision clinic?

To explain the nature of the patient's visual impairment (D) Signup and view all the answers

What is the primary cause of color vision loss in low vision patients?

Damage to cone photoreceptors and their neural network (A) Signup and view all the answers

What is the relationship between the decimal notation and LogMAR notation for visual acuity?

There is no direct relationship between them. (B) Signup and view all the answers

What is the main reason why a line of 6/60 letters would need to be longer than a line of 6/3 letters?

To compensate for the smaller size of the letters. (A) Signup and view all the answers

Why are pseudoisochromatic plate tests generally considered inappropriate for evaluating color vision loss in patients with low vision?

They do not accurately measure the type of color vision loss seen in low vision patients. (C) Signup and view all the answers

What is the main benefit of using a digital test chart with adjustable parameters?

It allows for personalized testing tailored to the individual's needs. (D) Signup and view all the answers

Which of the following color vision tests are considered more appropriate for detecting acquired color vision deficits in low vision patients?

Farnsworth 100 hue and D15 tests (B) Signup and view all the answers

What is the main reason why conventional color vision tests become unreliable for patients with low vision?

Their visual acuity is too low (B) Signup and view all the answers

How does a bioptic telescope work?

Enlarges objects by using a system of lenses. (D) Signup and view all the answers

What are the main features of a bioptic telescope?

It is a miniature telescope mounted in a spectacle lens that enhances vision for distant objects. (C) Signup and view all the answers

What is a dichromatic confusion line?

A line where a person with a color deficiency sees two colors as the same. (B) Signup and view all the answers

What is a key characteristic of the PNAC chart in comparison to the Bailey-Lovie near chart?

The PNAC chart uses related three-, four- and five-letter words on each line. (D) Signup and view all the answers

What is the recommended working distance for the acuity charts mentioned in the text?

40 cm (A) Signup and view all the answers

What is the purpose of the reverse contrast facility in the acuity charts?

To assist patients who find reflected glare from the white page uncomfortable or debilitating. (C) Signup and view all the answers

What is the recommended procedure for near vision testing?

First complete an accurate refraction, then assess near vision. (D) Signup and view all the answers

What is the standard practice in the UK for increasing the strength of the near addition during near vision testing?

Increasing in +4.00 steps until desired acuity is achieved. (C) Signup and view all the answers

What is the purpose of evaluating reading speed and fluency using tools like Pepper, MN read cards, or in-house equivalents?

To assess the patient's ability to read at a comfortable pace and with good comprehension. (B) Signup and view all the answers

What is the relationship between the printed versions of the original on-screen reading speed test?

Printed versions have been shown to achieve comparable results to the original on-screen test. (C) Signup and view all the answers

What is the main purpose of the acuity charts mentioned in the text?

To measure a patient's ability to see fine details at near distance. (D) Signup and view all the answers

Flashcards

Counting Fingers (CF)

A common term used in the UK for extremely poor vision.

Hand Movements (HM) vision

Classification of vision when movement can be detected at low acuity (less than 0.5/60).

Perception of Light (PL)

Vision classification when a patient can perceive light but it may not have directional sensitivity.