Etymology of "nasal specs" as a synonym for "nasal cannula"?

Solution 1:

Nasal cannulas are medical devices used when people are unable to get sufficient oxygen to keep their body functioning optimally, whether that's due to a condition like chronic obstructive pulmonary disease (COPD), another respiratory disorder, or an environmental change. verywellhealth.com [with photo]

Dual prong nasal cannulae or 'nasal specs' actually perform like a variable performance mask. Peter Driscoll et al.; Safe Transfer and Retrieval

Nasal cannulae should be position with one cannula in each nostril... The oxygen tubing should be places over and around the patient's ears, and secured under the chin (like wearing a pair of glasses). Hence they are colloquially known as nasal specs. T. Martin; Aeromedical Transportation

I was wondering whether there is also a connection to the instrument, a nasal speculum, but the only connection I've found so far is this example of "specs" short for (vaginal) specula:

Single-use speculum eliminates the time and expense of reprocessing metal specs AxiomMedicals

speculum (plural specula also speculums)

An instrument inserted into a body passage especially to facilitate visual inspection or medication m-w