You can see light at any range
I did some googling, and while it's pretty hard to find specific citations from scientific studies, the places that I've been able to find say that the human eye can see a candle from somewhere between 10 and 30 miles away. The curve of the Earth is about 3 miles away. Thus, any significant light is at least barely visible from any range that you're likely to have line of effect. The houserule that I've used for a while now is that you can see a light source at ten times the distance that you can see a non-lit object without penalty.
That said, the vision rules in every edition of D&D that I've seen are actually reversed. They only work if both the looker and the looked-at are in the same lighting conditions. The vision rules on PHB 183 state:
In a lightly obscured area... creatures have disadvantage on Wisdom(Perception) checks that rely on sight.
A creature in a heavily obscured area effectively suffers from the blinded condition.
Nothing in those rules says that you can't see a creature if that creature is inside darkness and you aren't. This is clearly ridiculous. This weirdly reversed rule has existed since at least 3.0, and shows how little the designers thought about what to do about differing light conditions.
What this means is that you should rely on your intuition more than the rules for what will give penalties based on vision. Since, IRL, lights can be seen from the horizon, you can probably see someone with a torch from at least a few hundred feet, probably out to a mile or so.
As far as being blinded is concerned, my intuition was always that that penalty happened because you couldn't see the ground beneath your feet, or the things that are around you. Thus, I would rule that a character who can see a light hundreds of feet off is still blinded, except for the purposes of making checks or attacks against targets who are lit up.
Interesting point regarding the description of darkvision on PHB p. 184. However, the Monster Manual on p. 9 says:
Darkvision
A monster with darkvision can see in the dark within a specific radius. The monster can see in dim light within the radius as if it were bright light, and in darkness as if it were dim light. The monster can't discern color in
darkness, only shades of gray. Many creatures that live underground have this special sense.
This definition matches the PHB definition on p. 20. Comparing the PHB p. 20 and MM p. 9 definitions on the one hand with the PHB p. 184 definitions on the other, the only part in discrepancy is the part about "see in dim light within the radius as if it were bright light." The omission from p. 184 is only that, an omission. It isn't a contradiction.
It's reasonable to conclude that by RAW darkvision is darkvision, and works the same for every creature, unless otherwise noted in the creature's description.
The description on PHB p. 184-185 was corrected in this errata, which says:
Darkvision (p. 185). The definition of darkvision here now matches the definition everywhere else in the game (6th printing).
In summary, the definition of darkvision listed on p. 20 of the PHB is correct, and the omission on p. 185 was corrected in errata.
Best Answer
The standard rules for Darkvision apply
The description of Darkvision says:
The description for the Twilight Cleric simply says you have Darkvision and doesn't go on to modify that in any way. Darkvision doesn't allow you to discern color.