Apple's iOS running on the iPhone, iPad and iPod Touch changed very little since it was lauched in 2007. It had a few minor tweaks with every new versions, but it still had the same menus and icons. It looked pretty much the same in 2013 as it did in 2007.
When iOS 7 was launched it brought a radically new interface that is very different to what we had previously seen on Apple's mobile devices and tablets. For the most part, the changes are good, but it isn't perfect and there are a few annoyances.
One is that the new interface can be hard to read in some places. This is because of the fonts and colours that are used. The fonts used are sometimes very thin and in places you get light text on a light background, very tiny fonts that are hard to read, and wallpaper that interferes with the text.
Fortunately, these problems can be fixed and iOS 7 is more customisable than previous versions. The wallpaper on the home screen needs to be selected carefully or you won't be able to read some of the names underneath the app icons. Go to Settings, Wallpapers and brightness. Tap a screen below Choose Wallpaper and then select on that isn't too busy. Plane colours are best and predominently dark or light works well.
The most interesting and useful options are in Settings, General, Accessibility. Two really useful options are Bold Text and Increase Contrast. These make the text much more readable and together they make the iPhone and iPod Touch much more usable. You should really try these two settings and they make a significant difference. The iPad's screen is bigger and it doesn't suffer as much from small text (the iPad mini moght though), but try the settings anyway.
(On a slightly different subject, notice how Bold Text is a simple switch, but Increase Contrast says on, and pressing it goes to a new screen where there is switch. Why not put the switch on the first screen, why go to a second screen? It's strange.)
There is also a Larger Type option here and it can be useful. It does not force apps to use a larger font, so apps can ignore it. Some do take note of this system setting though and they display larger text, which can help readability. Tap it and turn it on. There is a slider to select the preferred font size. (Another strange feature is that there is another Text Size option in Settings, General. It looks the same, except there is no on/off switch.)