Sight Rot

This painful infection causes bleeding from the eyes and eventually blinds the victim. A beast or humanoid that drinks water tainted by sight rot must succeed on a DC 15 Constitution saving throw or become infected. One day after infection, the creature’s vision starts to become blurry. The creature takes a -1 penalty to attack rolls and ability checks that rely on sight. At the end of each long rest after the symptoms appear, the penalty worsens by 1. When it reaches -5, the victim is blinded until its sight is restored by magic such as lesser restoration or heal. Sight rot can be cured using a rare flower called Eyebright, which grows in some swamps. Given an hour, a character who has proficiency with an herbalism kit can turn the flower into one dose of ointment. Applied to the eyes before a long rest, one dose of it prevents the disease from worsening after that rest. After three doses, the ointment cures the disease entirely.

Magical Contagion

Any Beast or Humanoid that drinks water tainted by Sight Rot must succeed on a DC 15 Constitution saving throw or have the Blinded condition until the contagion ends. Fighting the Contagion. Magic such as a Heal or Lesser Restoration spell ends the contagion immediately. A character who is proficient with an Herbalism Kit can use it to create one dose of nonmagical ointment, which takes 1 hour. When applied to the eyes of a creature suffering from Sight Rot, the ointment suppresses the contagion on that creature for 24 hours. If the contagion is suppressed in this way for a total of 72 hours (requiring three doses and applications of the ointment), the contagion ends on the creature. Spreading the Contagion. Any Humanoid that makes skin contact with a creature infected with Sight Rot must succeed on a DC 15 Constitution saving throw or also become infected with the contagion. On a successful save, the Humanoid can’t catch the contagion from that particular infected creature for the next 24 hours.