My eyes are getting worse by the year for close up stuff. I have gone from using a clip on hat magnifier to carrying a set of readind glasses. You might try a threader fly box . With a threader fly box you could get the the tippet through the eye of the fly and then learn to tie a simple but strong knot like a figure 8 loop knot or surgeon's loop knot which work fine with trout sized flies
The Davy Knot is also a simple strong Knot

[This message has been edited by okflyfisher (edited 07 July 2006).]