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Head-to-toe assessment and vital signs

How to test visual acuity with a Snellen chart

Other platforms explain it with text and video. In Making Synapses you practice it on the patient.

MD / DOPANursing (NCLEX)
Practice it in VR with Blocky

Visual acuity is the vital sign of the eye. Test it in every eye complaint.

What you need

Step by step

  1. Set up

    Chart at 20 feet (6 meters), good light. [1]

  2. One eye at a time

    Cover the other eye without pressing. [1]

  3. With glasses

    Test with distance glasses if they use them. [1]

  4. Read down

    Smallest line with most letters correct. [1]

  5. Pinhole

    If worse than 20/20, repeat through a pinhole: improvement suggests a glasses problem. [1]

  6. Record

    For example 20/40 right eye with glasses. If no line, count fingers, hand motion or light. [1]

Common errors

Practice it in Making Synapses

In Making Synapses you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.

Making Synapses cases that train this skill

29 Making Synapses cases train this skill: open the case library

Sources

  1. Open RN, Nursing Skills 2e (Chippewa Valley Technical College) (CC BY 4.0)
  2. OpenStax, Clinical Nursing Skills (reference)

Steps adapted from Open RN, Nursing Skills 2e (Chippewa Valley Technical College), licensed under CC BY 4.0. Facts and steps also follow OpenStax, Clinical Nursing Skills (reference). Making Synapses is not affiliated with these organizations. Updated: 2026-10-11.