In the wilderness improvisation is the key. How can one use this obsolete technology in the practise of Austere Medicine?
Most of us will have a head torch or a hand torch when practising our medical skills in remote and austere environments. Additionally, most of us will have something in our survival kits that could be used as an improvised head mirror.
Using a signalling mirror for an improvised otoscope and diagnostic tool takes a bit of practise. You have to have a light source coming from behind the patient. The sun would be a good option except that here in County Kerry, Ireland we rarely see the sun at all.
An ingenious use of a hand torch could be substituted for the sun. Have someone hold the torch above the casualties head. Aim the torch directly at you. Bounce this beam of light using your signalling mirror into the ear, nose or throat that you wish to assess.
Remote and Austere Medicine excels on improvisation and relearning some of these old diagnostic tricks. Find an old pre 1985 medical textbook for a lot of hints and tricks of how to practise medicine without the use of modern diagnostic toys.