As WR2 stated, with a couple of additional ideas.
(1) a laptop with the SB I3 (the biggest screen i think is a 17 in, Tosihiba did make a 18" but it was rather expensive) and has HDMI out. For internet, email, and uSoft word you can enlarge the size upto 400%.. You can also enlarge the icon.
(2) With the HDMI out you could hook the laptop upto a 27-> 32 inch TV which would make everything bigger and if need then enlarge as I indicated in (1). A 2nd option is the Samsung 27" P2770HD. This is a monitor/HDTV. Only draw back is that it only has one HDMI input (also has 1 Ant input, one Dvi and one PC input). I have one with a Stand-alone DVD recorder w/cable input, Two computers, and an external Antenna connected to it).
?? budget ??
For $600: I3-2410M with HD3000 ICP and a Blu-ray/DVD drive, and HDMI output.
http/www.newegg.com/Product/Product.aspx?Item=N82E16834214407
If connecting to a tv then 1 15.6" laptop will be a little cheaper (make sure it has the I3-2410M CPU)
The acer (not my choice @ $450 and an HP @ $480) neither of these 2 has the Blu-ray DVD drive which normally adds about $100 to cost.
http/www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100006740%20600004344%20600004378%20600003986&IsNodeId=1&name=Intel%20Core%20i3
A TV, unless you have one will add about $300 to $450 depending on if it is 720 P or 1080P. Really only need the 1080 to watch High def TV (normally 1080i or p) and blu-ray. With decreased vision would recommend the cheaper 720.
PS I mother has this problem but at the point that even a 32 IN tv display does not help.