Final answer:
Yes, it is possible to estimate PD without a pupillometer using methods such as measuring the distance between corneal reflections or utilizing smartphone apps or online tools.
Step-by-step explanation:
The corneal reflection method is a technique used to measure the pupillary distance (PD). It involves shining a light towards the eye and observing the reflection on the cornea. A pupillometer is commonly used to accurately measure the PD, but it is possible to estimate PD without a pupillometer.
One way to estimate PD without a pupillometer is by using a ruler. By measuring the distance between the two corneal reflections in millimeters, the PD can be calculated. Keep in mind that this method may not be as precise as using a pupillometer, but it can still provide a rough estimate.
Another method is to use a smartphone app or online tool specifically designed to measure PD. These tools utilize the camera on the device to capture an image of the eye and calculate the PD based on the distance between the reflections.