I've used those telescoping reading glasses for over a year now and they have held up very well. The case is great and to my surprise, the telescoping arms have not come apart. A bit heavy for backpacking IMO.
Somebody in another thread posted a link to these a while ago and I'll pass it on to those of you with aging eyes that want the lightest solution. These work great for casual use and fit in the card holder that I use to carry my ID when on the trail.
http://www.leevalley.com/en/wood/page.aspx?cat=1,43456,43351&p=55986
Trail Designs also carries them and they offer a hard case option which would be nice.
http://www.traildesigns.com/accessories/ultralight-glasses