Optic nerve (CN II) pathology such as optic neuritis.Retinal diseases such as age-related macular degeneration.Ocular media opacities such as cataract or corneal scarring.Assess if they can detect light from a pen torch shone into each eye (“Perception of Light”/”PL” or “No Perception of Light”/”NPL”).ĭecreased visual acuity has many potential causes including: Assess if they can see gross hand movements (recorded as “Hand Movements” or “HM”).ĥ. Assess if they can count the number of fingers you’re holding up (recorded as “Counting Fingers” or “CF”).Ĥ. Reduce the distance to 1 metre from the Snellen chart (1/denominator).ģ. Reduce the distance to 3 metres from the Snellen chart (the acuity would then be recorded as 3/denominator).Ģ. If the patient is unable to read the top line of the Snellen chart at 6 metres (even with pinhole) move through the following steps as necessary:ġ.

When recording the vision it should state whether this vision was unaided (UA), with glasses or with a pinhole (PH).įurther steps for patients with poor vision.

If the patient gets more than 2 letters wrong, then the previous line should be recorded as their acuity.

If the patient reads the 6/6 line but gets 2 letters incorrect, you would record this as 6/6 (-2).

Visual acuity is recorded as chart distance (numerator) over the number of the lowest line read (denominator): Repeat the above steps with the other eye. You can have the patient read through a pinhole to see if this improves vision (if vision is improved with a pinhole, it suggests there is a refractive component to the patient’s poor vision).ĥ. Record the lowest line the patient was able to read (e.g. Ask the patient to cover one eye and read the lowest line they are able to.ģ. Stand the patient at 6 metres from the Snellen chart.Ģ. If the patient normally uses distance glasses, ensure these are worn for the assessment.ġ. Visual acuity Assessment of visual acuity (distance)īegin by assessing the patient’s visual acuity using a Snellen chart. You might also be interested in our OSCE Flashcard Collection which contains over 2000 flashcards that cover clinical examination, procedures, communication skills and data interpretation.

Pupillary reaction test