This Instructable describes a method of making a paracord lanyard to help keep your glasses on, or near, your head. Based on your adjustment of the cord, the glasses can either dangle on your chest, or be held snugly to the face. This method uses only paracord; some alternative approaches that incorporate additional materials are shown at the end.
Step 1: Materials
Paracord, about 1 yard (or 95cm)
Eye glasses or sunglasses (if you don't have these, well, why bother?)
Lighter (to singe cord ends)
Knife or Scissors (unless you have really sharp teeth)
Plastic Cord Lock
Step 2: Getting Started
Begin with a 3' (~1m) length of paracord. Snip it in half and singe the ends so they won't fray.
Next lay the two pieces parallel to each other on a flat surface.
Step 3: The Figure 8 Knots
You're going to tie two Figure 8 knots, one in each piece. Start with the right end of the piece nearest you, and follow the detailed Instructions in the pictures below to tie the knot.
Step 4: Repeat
Now, using the left end of the second cord, tie a figure eight knot around the first piece, just like you did in the previous step. The two knots form the stops at the end of the joined pieces.
Step 5: About Tightness
Since the cords need to slide for the adjustment, make sure your figure eights are neither super tight, nor too loose. You should be able to gently slide the knots together and apart. This will shorten or lengthen the overall joined piece. If you have unsightly ends dangling from your knots, you can snip and singe them in place.
Step 6: Preparing the Ends
This is done by forming a small noose at each end of the joined piece. It's not really a noose because it only has two turns, but otherwise it's pretty much the same knot. To find where your end knots should be placed, pull the two figure eights knots so they're about 6" (15cm) apart, and place behind your head. Grab each end just above and behind your ears. This is about where the knot should be. Don't worry about being exact, it's adjustable!
To make the mini-nooses, follow the steps in the pictures.
Step 7: Attach This End
Slip the "noose" over the ear piece of your glasses, and tighten. The whole knot should tighten up nicely as you pull on the long end..
Step 8: Repeat.
Repeat this process (steps 6 & 7) on the other end of your lanyard. Pretty simple, huh?
Step 9: ...and You're Done.
Ta-da! Remeber, by sliding the two Figure 8 knots together, you can snug the glasses to your face. This can be particularly helpful if someone has irresponsibly let your youngest brother drive the boat you're on. Trust me.
Step 10: But Wait, There's More...
If you have an old cord lock, or even a bead with the right aperture, you can forgo the whole figure 8 business, keep your cord as a single piece, and use that hardware to adjust your snugness.
Step 11: ...and That's Not All.
If you're feeling fancy, you can attach the cords to your ear pieces so that they don't protrude. Even though it looks a little neater, this makes the cord harder to put on and remove from the glasses, so I opted for the simpler method above.
Step 12: There You Have It...
... a couple of ways to keep your glasses close at hand.
(This is my first substantial Instructable; please rate! Thanks!)