These are my "visitor binoculars", which often end up being used by small children.
Small children tend to wear wooly mittens, which are not so good for focusing binoculars, and a bit slippery, so I used a bit of the ever-popular Sugru to modify the binoculars and make them easier to use.
Step 1: Sugru
Sugru instructions are available on their website and on the packets:
For best results, we suggest washing and drying your hands before use.
1. Choose the sachet size you’d like to use and cut open with a scissors
2. Roll the sugru in your hands to limber it up … 30 seconds should be more than enough
3. Apply and form sugru …in your own style ! After approx 30 mins it will start to cure. At that point, it’s best to stop reforming sugru.
4. Leave to cure overnight: it will cure 3mm deep in 24 hrs, and deeper pieces may take longer.
tip! Use sugru at 21°C if possible. Warm conditions will speed up cure time and cold will slow it down…
Step 2: Sausage
I rolled about a third of a 5g sachet into a long thin sausage, and then wrapped it carefully around the focus-wheel of the binoculars.
I pressed it into place in the grooves of the focusing wheel, making sure that the Sugru did not jam between the wheel and the body of the binoculars.
Step 3: Notches
Adding the Sugru makes the wheel easier to turn through the principle of leverage, but it also needs some grip.
I went around the wheel, cutting notches out of the Sugru with a craft knife.
If you do this, you will find it impossible to turn the wheel without mushing the Sugru. When you cut a notch, press the blade of the knife carefully into one of the notches already moulded into the wheel, and use the edge to carefully turn the focussing wheel far enough to cut the next notch.
Step 4: Grip
Having seen children struggle with the binoculars in mittens, I knew that the problem was reaching over the bulky section of the binoculars in slippery gloves.
This was easily solved by adding two strips of Sugru, one to the top of each barrel, to stop the kids' slippery gloves losing their grip on the binoculars.
After curing, I tested the modifications by using the binoculars myself, wearing oven gloves (no, there are no photos of this), and they worked.
I also believe modifications like this would make binoculars easier to use for people with a weak grip, but these particular binoculars are quite old, and too heavy for such users anyway.
Maybe you'd like to make similar modifications to lighter binoculars, and let me know how they go?