A little (maybe) inside story here
Believe it or not, I guess Google globally adjusted it's box height after Google China added 6px to its search box height.
On 13th April this year there's a post on a extremely popular & influential IT commentary news site in China
http://www.cnbeta.com/articles/81765.htm
saying that Google.cn failed to match Baidu.com because their search box is so small that people need exta time to move the mouse to focus the correct text box
6 days later Google.cn improved one of their page(specifically http://www.google.cn/hp?sp=china) accordingly
http://www.cnbeta.com/articles/82222.htm
Next on 6th October Google.cn switched to bigger search box on all of their pages, including the google.cn home page
http://google.org.cn/posts/google-china-bigger-search-box.ht...
Finally on 10th September Google globally adopted this design change
http://cnbeta.com/articles/93034.htm
Coincidences?
http://www.scientificamerican.com/article.cfm?id=why-does-ey...
"When the lens loses its pliability it also loses its ability to focus over a wide range of distances. A hardened lens becomes more fixed on distant objects and cannot focus as well on nearby objects or vice versa."
So, yes, larger fonts will help.
By the way, I'm speaking from experience here. I'm 43, which I don't think is quite "elderly", but presbyopia has hit me pretty hard in the past year. My eyes are still better than 20/20, but I now need reading glasses for up-close work. Without my glasses, small fonts can be a problem.