I love this idea of a love note disguised in an eye chart. It is one of my favorite DIY projects. I made this one year for my husband on our anniversary and hid a little love note within the eye chart and we have been displaying it ever since.
You can disguise any note really, it just has to simply fit within the perimeters of a simulated eye chart. All you need to make this is a computer and a printer. The most time consuming part is just trying to space everything out evenly onto a word document.
First things first I checked the internet for examples of eye charts: