Vision Types

Niya-Yur Vision Types

• Ultravision (aka low-light vision)
• Darkvision (aka infravision)
• Supravision (aka all visions plus more)
• Truevision (aka magical sight)

Darkvision

Many creatures in fantasy gaming worlds, especially those that dwell Underground, have Darkvision. Within a specified range, a creature with Darkvision can see in Darkness as if the Darkness were dim light, so areas of Darkness are only lightly obscured as far as that creature is concerned. However, the creature can’t discern color in Darkness, only Shades of Gray. (PHB pg 183). Darkvision is essentially infravision, similar to modern night-vision goggles. Works everywhere even in the deep underground because there is a lot of heat variation to materials and beings.

Ultravision

Ultra violet light vision, aka low-light vision, works on the color spectrum in the higher ranges but provides a washed-out color sight. Works everywhere even in the deep underground because there is a lot of heat variation to materials and beings.

Truesight

A creature with Truesight can, out to a specific range, see in normal and magical Darkness, see Invisible creatures and objects, automatically detect visual illusions and succeed on Saving Throws against them, and perceives the original form of a Shapechanger or a creature that is transformed by magic. Furthermore, the creature can see into the Ethereal Plane. (PHB pg 184)

Supravision

Supravision is the ability to see throughout a large range of the electromagnetic spectrum. It has all the advantages of infravision and passive ultravision, plus a few others. Beings with supravision could even see radar (which is often microwave radiation). Though they can almost see X-rays, they do not have 'X-ray vision'. The greatest advantage to supravision is that a creature with it cannot be blinded, except by nuclear detonations and similar powerful effects, because their eyes would switch over to a different part of the spectrum. Creatures with supravision can also see the different flavors of magic, as well as heat sources, and are completely at home in broad daylight, at night, or in total (relative) darkness.(Sister Worlds - AD&D Vision Types, June 2021)

Niya-Yur Species Vision Types

• Elves Darkvision 60ft (PHB pg 23) Ultravision 60ft, character does not have disadvantage in dim light scenarios
• Dwarves Darkvision 60ft (PHB pg 20)
• Goblins Darkvision 30ft
• Hobgoblins normal vision
• Humans normal vision
• Gnomes Darkvision 60ft (PHB pg 37) 30ft
• Yhatnar normal vision

Vision Details

Low-Light Vision

Low-light vision was a good ability as it allowed as its name suggests, a race to see better and further in low (or dim) light.
This is how low-light vision appears in D&D 3rd edition for elves:

low-light Vision: An elf can see twice as far as a human in starlight, moonlight, torchlight, and similar conditions of poor illumination. She retains the ability to distinguish color and detail under these conditions.

We can easily bring this into D&D 5th edition by almost keeping it as is.
D&D 5th Edition Conversion Here is the 5th level conversion:
Low-light Vision. You can see twice as far in dim light. You retain the ability to distinguish color and detail under these conditions.
This would allow elves, for example, to double the distance they can see in dim light.
A torchlight is bright out to 20ft and then dim out to another 20ft (40ft from the person holding the torch). With low-light vision, the torch-holding elf could see 20ft in bright light and 40ft in dim light (out to 60ft from where they are standing).
They still receive the disadvantage for perception checks in dim light (but then so do races with Darkvision) – the only thing they cannot do is see in complete darkness, which makes sense for surface-dwelling elves and half-elves.
Design Note: You could say that characters will low-light vision don’t have disadvantage in dim light instead of extending the range. This would be a good trade-off with Darkvision.

Races with Darkvision

The following races currently have Darkvision in D&D 5th RAW:

• Dwarves – out to 60ft
• Elves – out to 60ft (except Dark Elves, who have it out to 120ft)
• Gnomes – out to 60ft
• Half-Elf – out to 60ft
• Half-Orc – out to 60ft
• Tiefling – out to 60ft

Out of these races, I see the Dwarves, Half-Orcs, and Tieflings having Darkvision and the others having Low-Light Vision.
I am not sure why Elves (with the exception of Dark Elves), Half-Elves, and Gnomes would receive Darkvision.
You could argue that Rock Gnomes would have it, but given it’s a Gnome trait (and not a sub-class trait) this seems more difficult to change.
This is part of the reason I have major issues with D&D Gnomes, and why I use my own Gnome variant in my campaign world, instead of those in the PHB.
Conversion for this would be quite simple – just replace dark vision with Low-Light vision for the following races: Elves (with the exception of Dark Elves), Half-Elves, and Gnomes.
Design Note: You could see low-light vision as something that is not as good as dark vision and want to compensate the race for this change, but I don’t see it as that big a shift. But if you do want to, you could always give them a skill or tool proficiency in addition.

Reasoning

When D&D moved to the newer, simpler 5th edition they disregarded a lot of the nuance that made the earlier editions of D&D more detailed.
This made the game simpler, but it lost a lot in the process.
An example of this is darkvision and the lack of, what was in 3rd edition, low-light vision.
Low-light vision gave someone the ability to see better in, well, low-light conditions.
When 5th edition rolled around, it did away with low-light vision and just gave almost all races Darkvision instead – for simplicity.
This is one of the areas where the simplicity of 5th edition fell down as elves and half-elves, who once had low-light vision, ended up with darkvision instead.