U can get the eye diagram simply by taking the output of your transient simulation( I don't know how to do that in eldo) and using matlab(for example) split this output into intervals equal to the period of your signal and plot those intervals over each other.
If you are using eldo , then I suppose you have ezwave viewer.
In ezwave, choose the signal you want , then choose the eye diagram function from the "Tools" menu . A dialog box appears, set the period, the start time , end time and offset . Then plot the eye-diagram. You may need some fine tuning to get the result you are looking for.
U can see the eye diagram in cadence vy doing Transient simulation.
After completing simulation go for the Special calculator.
In Special Calculator one option is there by name Eye diagram.
main thing is how to Interprit the Eyediaram.
I am attaching one PDF along with this post..Please see that.