Which bulb number is used in a non-contact tonometer?

In a non-contact tonometer, also referred to as an air puff tonometer, the specific bulb number used is essential for accurately measuring intraocular pressure. The bulb number 12419 is the correct choice because it is designed to produce the optimal air pulse needed for the non-contact measurement. This pulse creates a brief air jet that is aimed at the cornea, temporarily flattening it to gauge intraocular pressure without direct contact.

Other bulb options do not meet the requirements for non-contact tonometry since they are intended for different types of tonometry or have different pressure output characteristics that would not provide reliable intraocular pressure readings in this context. Therefore, understanding the specific application and design of the bulb types is crucial for proper tonometric measurements in an ophthalmic setting.