Ishihara chart is used for the assessment of.

Appeared in: Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Explanation

The Ishihara chart is the standard screening tool specifically designed to assess for color vision deficiencies.
It consists of a series of pseudoisochromatic plates, which are circles filled with dots of different colors and sizes, as shown in the image.
Individuals with normal color vision can discern the numbers or patterns within the dots (like the number '74' in the example image).
Those with red-green color blindness, the most common form of color deficiency, will be unable to see the figure or may see a different figure.
The test evaluates the function of the cone photoreceptor cells in the retina, which are responsible for color perception.

Option A: Night blindness (nyctalopia) is the inability to see well in low light. This condition is related to the function of the rod cells in the retina, not the cone cells that detect color.
Option C: This option is incorrect because the Ishihara chart is a specialized test for color vision only and has no role in assessing night blindness.
Option D: This option is incorrect because Option B, 'Color vision,' is the precise and correct answer.

Clinical Relevance

Nursing practice connection: Use the key finding related to Assessment of color vision using the Ishihara chart to guide bedside assessment, documentation, and the next nursing action.
Screening for color blindness is crucial for patient safety and career counseling, as certain professions (e.g., pilots, electricians, surgeons) require accurate color discrimination.
While most color vision defects are congenital (inherited), acquired defects can be an early sign of underlying disease (e.g., optic neuritis, macular degeneration) or drug toxicity (e.g., from digoxin or ethambutol).
A nurse should be aware that a patient's inability to distinguish color-coded medications or equipment could pose a significant safety risk.

How to Approach the Question

This is a factual recall question combined with an image interpretation.
First, identify the key term in the question: 'Ishihara chart'.
Next, analyze the image. The image shows a circle made of multi-colored dots with a number hidden inside. This is a classic visual cue for a color perception test.
Recall the primary function of the Ishihara test. It is one of the most common tests taught in nursing for assessing vision.
Evaluate the options based on this knowledge. 'Color vision' is the direct and specific purpose of the test.
Eliminate 'Night blindness' as it relates to vision in dim light (rod function), not color (cone function).

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 2 Part 1 p. 87-89

E6 Medicine Harrison 22e Part 1 p. 263-265

Practise the full Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Attempt every question from this paper in a timed mock, then review the full solution for each one.