Putting substances in your eye with an unknown purity is plain and simple idiocy. You could potentially lose your sight, or at the very least cause some irritation. Think about how fun it will be to be tripping balls, all the while being fixated on the irritation in your eye... So, plainly, DO NOT PUT DRUGS IN YOUR EYE UNLESS DIRECTED TO BY A PHYSICIAN OR IT IS INDICATED ON THE PACKAGING MATERIAL OF NON-ILLICIT DRUGS.
Some people report plugging LSD to be superior to oral or sublingual ingestion, so you might want to give that a try if you want to make the most out of your LSD, but really the bioavaliability is already relatively 100% of the dose to IV, for oral and sublingual. Reports of IV LSD seem to be mixed on a slight decrease in the time of the come up and no discernible change in timeline/dynamic, even, so I'd suggest just sticking to sublingual/oral dosing.
Increasing the dose of the LSD will only really increase the duration if the previous experienced dose with the same substance was toward the lighter end of the spectrum (8-10 hours potentially rather than 10-12 hours [+/- 2 hours] of a higher dose), or taken at a different time. Increasing the dose wont deviate far from its general depicted timeline, but it will obviously change the dynamic of the trip. How much of a change in experience is determined by the potency of the blotters along with a few other less significant factors (expectations, placebo, etc).