Methods on how to measure pupil size

Under Photopic conditions,

Steps:

1. Ensure subject is in a relaxed state, and instruct him/her to look in forward.

2. Make sure the overhead light is also turned on.

3. Use the Burton’s lamp to magnify the eye, specifically, the pupil of the eye.

4. Check the eye using PERRLA.

PERRLA

- Pupils
- Equal
- Round
- Reactive to
- Light and
- Accommodation

5. Check whether the subject’s pupils are there.

6. Check to see whether the subject’s pupils are both equal in size, and round.

7. Check that the pupils are reactive to light; when light is shone on the pupil, pupil would decrease in size.

8. Check for the accommodation of the pupils when eye is reading at near, or focusing something at near.

9. Place a ruler just above the pupil and measure the pupil size. Ensure free fingers are placed on subject’s face/cheeks to avoid shaky hands.

10. Read and record down the reading from the Burton’s lamp, since the magnifying glass on the Burton’s lamp can also be use to read off measurements from the ruler.