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I have struggled with using regular threaders and thin wire that I have bent in the middle to use as a threader, but I think I have found an ideal threader. I am able to thread 4-ply yarn, crochet thread, and I recently used it to thread my sewing machine.
It is a floss threader for my bridge work. It is called GUM Eez-Thru Floss Threader. There are probably other brands out there. These are made in the USA! They even thread seed beads on elastic thread. The other beads are small also!
I posted about this with pictures on my website, Brenda's Bric-a-Brac.
If you love to sew, but your eyesight makes threading a needle, put a piece of white paper behind the needle. The contrast will make it much easier to thread the needle. On a sewing machine, slide the paper between the needle and the presserfoot
Source: An article on how to live with diminished vision (common problem among the mature).
By MargaretGadd from El Paso, TX
You can use dental floss to thread needles. Put a loop of it through the needle and use it as a threader to pull the thread through the sewing needle. Those cheaply made metal ones always break.
By Robyn 
If you're having trouble threading needles, buy some with slots at the top. Just insert thread from the top. The thread won't come out unless you tug on it.
When hand sewing, I am partial to quilting, I like to thread several needles to be ready when I have finished with one length of thread. To be even more organized, I prefer to use a magnet to keep the needles and threads straight so I don't have to stop what I am doing just to thread another needle. Saves me so very much time and I don't have to search for where I left off anymore.
When I have gone through all my needles, it's time to get up and move around anyway so I am pleased with this arrangement. :)
My grandmother couldn't see too well, but she was always hand sewing something. I suggest that when you visit a legally blind person who likes to sew, help them out by putting several needles on a spool of thread. They can take off one at a time with more needles to use as they need without having to thread them.
One way to easily thread a darning needle with a large eye is to fold a thin, rectangular sliver of paper in half the long way, sandwich the end of the thread into it as you would a hot dog in a bun, then slide paper and thread through the eye of the needle.
When starting a large hand sewing or needlework project, thread several needles when you begin. Then you won't have to stop and keep threading needles as you work.
If you cannot see well enough to thread your yarn directly into a big eye needle, and have a hard time pinching the end to make it fit into the eye, you can make simple needle threaders using a piece of thin but stiff plastic, such as those that come in product packaging.
Just cut it into strips, up to two inches long, and up to one inch wide. Fold each strip in half, as you would a hot dog bun, making a permanent crease. Sandwich the end of the yarn into the strip, as you would put a hot dog into the bun, making sure the tip of the yarn does not go beyond the tip of the threader. Slide the strip-encased yarn through the eye of your needle until you are certain the yarn is threaded through, then pull the strip free. Alternatively, you can first slide the empty folded strip part way through the eye, unfold the other end, clasp the yarn inside it, then slide it through.
By Sharon from Nampa, ID
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