What happened to Jenna on Pretty Little Liars?

Answer 1

Alli and her posse (Aria, Emily, Spencer, and Hanna) were all trying on clothes when Alli shrieks, "Toby!" and points. Toby is standing outside watching them, smirks, and runs away. Alli decides to get even. Toby is obessed with fireworks, so Alli steals one, and lights it outside of his treehouse (it's different in the TV series, but the outcome is the same) to scare him. Alli gets distracted by seeing Toby doing something just as bad. The firework suddenly gets out of control, and shoots inside the treehouse, lighting it on fire, and causing an explosion. The parents of Toby rush outside, yelling. Alli runs away, and all the girls are scared. Turns out, Jenna was inside the treehouse, and the blast blinded her. She was taken to the hosipital, and came out okay, but still blind, nevertheless.

Answer 2

What happened to Jenna on Pretty Little Liars is that Alison and her friends thought they saw Toby looking at them while they were getting undressed. They felt uncomfortable and wanted revenge. They took something to light a fire and Jenna was in the house at that time and got blind. If you watch the episodes you always see her with the walking stick and its because she is blind. Alison's friends never like to talk about it anymore. They call it "the Jenna thing"