You can do this yourself, and it is fairly easy, though a bit time consuming... You have two options, and I would recommend the 2nd:

• Open the theme you want big buttons in within Skin Studio (right click on theme within WB and select edit, or open Skin Studio and open the theme)
1. Navigate to: Edit Titlebars and WindowFrames - Edit Per Pixel Buttons (I use the advanced settings [I am an experienced user...] and basic will be selected by default... if you can't find the proper category in basic, change to advanced via the Preferences menu). Select Edit Image.., which will open the image, by default, within Paint.  You will then need to zoom to 800x (the max), and every box you see is an individual pixel.  The outermost colored boxes are the border... simply create a bigger border and fill the expanded interior with a color of your choice.  Paint is a primitive image editing program and therefor does not recognize the Alpha channel, of which is used for differing levels of transparency, ranging from 0 (opaque) to 255 (completely transparent).  You can achieve full transparency within Paint by using Hot Pink [255(R),0(G),255(B].
2. Use Photoshop (or equivalent advanced photo editor) instead of Paint. While the instructions above will be the same, we must first change the default editor before starting them.  
• Go to: Tools-Preferences-Advanced.  Select Pick Custom App under Editing Images, and navigate to the folder where Photoshop is installed and select the Photoshop executable file.  
• Advanced Photo Editors must be able to open and save the .TGA extension, as this file type is required for the Alpha channel. Most are familiar with RGB [Red, Green, Blue; all in values of 0,0,0 [Black] to 255,255,255 [White]), however, there is a 4th channel, A [Alpha].  In photos, including video, RGB is represented by ARGB.  

Amen. 

joeKnowledge: Make your screen resolution lower. It will make all buttons and text larger and easier to see. I have done this on a few people I know that have a problem seeing and it works fine for them. Just a suggestion.

While this is a quick and easy fix, it does so at the expense of use experience with less space allocated for windows and lower video output quality. I personally wouldn't do it that way, however many others are fine with it that way... it comes down to personal preference and weighing the pros and the cons, whether quality or time spent is more important.