A vision is when a cursed individual is haunted or simply taken by glimpses or realistic memories of both past and future, which can link him to other victims or to the curse itself. It is featured significantly in both Ju-on and The Grudge franchises.
When a past and a present/future victim are able to see each other, their respective visions form an atemporal connection.
Occurrences[]
Ju-on film series[]

Tomoka's vision.
Kobayashi had a brief vision of Mar's murder in the house's bathroom. When Detective Toyama was reluctantly investigating the Saeki house after new murders had happened there, he saw a group of schoolgirls before meeting his own grown-up daughter Izumi. While in the house, Rika received a revealing vision of the curse's true purpose onto her. Concluding she needed to look through her fingers to see, Rika did so and saw herself as Kayako's ghost, haunting other victims including herself. Takeo then went downstairs to kill her, recriating his murder. While shooting a television show in the house, actress Kyoko Harase sat thoughtful at the yard, thinking about her upcoming child, and unaware of Kayako serving her son Toshio in the kitchen.
Kyoko accidentally dropped her water and Toshio turned around. Both TV presenter Tomoka and her partner Norikata (who did not stepped inside the house and was reached by the grudge curse through Tomoka) had horrifying, ominous glimpses of each other's deaths before they actually happened. Chiharu was haunted and disturbed by visions of the house before she was taken.
The Grudge film series[]

Karen experiencing a vision from the past.
When Karen Davis ran to the house following her boyfriend Doug, she was taken to the past, sometime after the Saeki murders. She saw Peter Kirk attempting to contact Toshio's mising parents, the boy the whole time noticing and looking at her. Kirk saw nothing but felt Karen's (or Kayako's) single breathe which led him to the closet, where he discovered Kayako's lying corpse. In the same vision, Karen saw Takeo's hanged body and a ghostly Toshio playing with it. Karen attempted to end the curse by setting fire to the house. From inside the ambulance, she had a new flashback and saw the Saeki family as if they were happy and alive once again (implying that she could have in fact ended the curse). Toshio turned and stared at Karen, before his smiling mother called him in.
Karen's sister Aubrey went to Japan to take her and eventually crossed paths with the curse. As she met Kayako's mother, Aubrey had a vision of Kayako's childhood as a demon vessel for her rituals. She later comfronted the curse and saw her sister going upstairs and calling for Doug, before meeting her own horrendous fate.