Many waveform viewing tools include a feature to take the output of a simple transient and present it as an eye diagram.  (They split up the waveform into sections and translate them back to the origin.)  Check the documentation for your viewer.

You can easily get overshoot from dv/dt feed-through of capacitors -- if your input rises quickly, and there is a capacitance (CGDO, for example) from the input to the output, that capacitance looks like a short for very fast signals / high frequencies.

You could perhaps add some series resistance to cut the feed-through.

Tfall/trise are too short for your circuit, but you'd have to look at the design specifications to know whether your circuit is poorly designed or whether you have chosen times that are faster than the required specifications.