How is the "Vision Score" calculated?

In one of the more recent patches, Riot Games added some more metrics to post-game analysis so you can determine how well you did in the match. One of those metrics is called "Vision Score". How is this value calculated? What does it mean?

Rioter Riot GMang, left a post here going over the specifics of how the vision score works. I will quote the relevant parts from his post as they explain it better than I could.

The TLDR: Vision Score is a loose measurement of vision game contribution, and can be ballparked as "about 1 point per minute of ward lifetime I'm responsible for providing/denying." It tends to be in the 5-150 range.

Vision Score System

The "scale" of the point system is "every point of Vision Score is about equal to one minute of ward lifetime in value." So if your vision score at the end of a game is 121, you can ballpark "my vision contribution this game was worth about 2 hours of ward lifetime." This number comes from three main sources:

• Ward Lifetime Provided: Each minute of ward lifetime you provide by placing wards will give you 1 point (can give fractions of points). There are actually a lot of modifiers to this score, see "Ward Lifetime Provided Modifiers" below.
• Ward Lifetime Denied: When you get a ward takedown (earned gold from a ward's death), you get 1 point for every minute of lifetime remaining on the ward (permanent wards are assumed to have 1.5 minutes of lifetime remaining).
• Vision Mechanics: Various vision-providing mechanics have a baseline score on-use (usually 0.1 to 0.5), and can also give bonus scores if revealing unseen champions or epic monsters (usually 0.1 to 1.0). This includes Scryer's Bloom, trinket activation, ward placement, Scuttler Ward, Ashe Hawkshot, Kalista Sentinel, and Quinn Heightened Senses. A Hawkshot that reveals a full Baron attempt will give much more than a Quinn W that reveals nothing (which will still give some score).

Ward Lifetime Provided Modifiers

The rule of "my wards give me 1 point per minute they're alive" actually has a bunch of rules that can reduce the score. Each of these reduces the score multiplicatively: if two rules each reduce the point value by 50%, the resulting ward will give 0.25 points per minute, not 0 points. Modifiers only apply to the value from their actual duration: getting a -50% modifier for 6 seconds will translate to -0.05 points, not a -0.5 reduction from the entire minute.

• Staleness: A ward that hasn't seen any interesting units (enemy champions, wards, and epic monsters) in a while will gradually go down in point value, starting at -0% at 60 seconds of staleness and worsening to -50% at 120 seconds of staleness.
• Redundancy: While a ward is near other friendly sources of vision (allied wards, structures, and lane minions), its point value will be reduced, starting at -25% for 1 redundancy and worsening up to -75% for 3+ redundancies. Lane minions don't count as redundant if the ward is in brush.
• Safety: A ward that's very close to your base can give less score, starting from -0% score around your buff camps and worsening to about -50% score at your base walls. Pointlessness: A ward that's very close to a friendly structure or inside your own base will have a -100% modifier to its point value. Baseline: If a ward is quickly killed by enemies, it will still give lifetime score as if it survived a minimum of 20 seconds (0.33 points).