The 1st-level Sor/Wiz spell ebon eyes [trans] (Spell Compendium 77) is a confusing mess, because, as written, it does allow the affected creature to see through natural and magical darkness. As the core rules place an otherwise high premium on the ability to see without a light source through natural darkness and even higher premium on the ability to see through magical darkness, it seems strange that a 1st-level spell should obviate both, but the spell ebon eyes does, and the spell does so apparently to the limit of the affected creature's normal vision.
"So ebon eyes is awesome?"
As written, yes. While there are many ways of gaining darkvision, gaining darkvision to the limits of normal sight is otherwise the sole the province of the obscure 4th-level Sor/Wiz spell superior darkvision [trans] (Unapproachable East 53). And while there are a handful of ways of gaining the ability to see through magical darkness, only the equally obscure 7th-level Sor/Wiz spell fiendish clarity [div] (Fiendish Codex I 94) allows seeing through magical darkness as if it were normal darkness, hence to the limit of the affected creature's darkvision (yet the spell itself only provides, among other effects, darkvision 60 ft.). For further comparison, the 3rd-level Fiendish Codex II spell devil's eye and the spell true seeing only allow seeing through normal and magical darkness out to, respectively, 30 ft. and 120 ft. Further, note that these spells are the best ways of almost duplicating the effects of the spell ebon eyes; domains, feats, and magic items are, objectively, worse at the task.
This makes the 1st-level spell ebon eyes the best see-in-the-dark spell printed for Dungeons and Dragons 3.5.
For a more conservative approach to seeing in the dark
It's true that the game overvalues the ability to see in the dark without a light source, and it's true that the game overvalues the ability to see in magical darkness. However, just because such abilities are overvalued doesn't change their values.
Thus a conservative DM may view the spell ebon eyes as, perhaps, a little unbalanced.1 For such a cautious DM, below are two options.
Consider using the original version of the spell ebon eyes...
When the spell appeared in the Dragon #322 article "Patterns of Shadows and Light: Same Coin, Different Sides" by Jason Nelson, it looked like this:
Ebon Eyes
Transmutation
Level: Assassin 2, Clr 2, Sor/Wiz 2
Components: V, S, M
Casting Time: 1 standard action
Range: Touch
Target: Creature touched
Duration: 10 min./level
Saving Throw: None
Spell Resistance: Yes (harmless)
The subject of this spell gains the ability to see normally in magical darkness and magical shadowy condition [sic], although it [the spell] does not otherwise improved the subject's ability to see in natural dark or shadowy conditions. While the spell is in effect, a jet-black film covers the subject's eyes, a visual effect that gives the spell its name.
Material Components: A pinch of powdered black gemstone of any type.
In other words, the Dragon magazine version is a low-level spell that grants the subject the ability to see normally only through magical darkness, to the limits of the affected creature's own vision. For example, in an area of magical darkness that's also naturally dark, a creature affected by the spell ebon eyes that lacks darkvision still can't see without a light source, but a creature possessing darkvision can see to the limits of its darkvision.
...Or just changing the first natural to unnatural
As written, the full Spell Compendium description of ebon eyes is, honestly, borderline gibberish, but change the first natural to unnatural and the spell's effect is a bit clearer:
The subject of this spell gains the ability to see normally in unnatural and magical darkness, although it does not otherwise improve the subject’s ability to see in natural dark or shadowy conditions. The subject ignores the miss chance due to lack of illumination other than total darkness.
Emphasis mine. A conservative DM could do worse than make this minor change.
1 Such a DM should, however, note that only the most unusual campaigns will be ruined by allowing such a low-level see-in-any-darkness spell. For example, in the core rules, even a low-level party can pay a 20th-level spellcaster 1,850 gp to cast on an object continual flame heightened to a 9th-level spell therefore eliminating most worries about magical darkness unless the object's specifically targeted by other effects.
Averting your eyes does exactly what it says it does: You willingly look away from your target.
Unless surprised, a creature can avert its eyes to avoid the saving
throw at the start of its turn. If the creature does so, it can't see
the medusa until the start of its next turn, when it can avert its
eyes again...
When you cannot see a target, you have disadvantage on attack rolls made against it (PHB p. 183) and many spells that require sight of a target will not work. If a spell indicates it affects a target that you can see, then it will not work if you avert your eyes. It's worth noting that averting one's eyes is not a common interaction in the game.
No, you cannot look at the floor and retain vision of her. If you avert your eyes, you cannot see her. If you choose not to avert your eyes, you might get turned to stone
Also, if you cannot see the medusa, she has advantage on attacks against you. PHB p. 195 :
When a creature can’t see you, you have advantage on attack rolls against it.
The same goes for monsters against you.
Best Answer
No, it wouldn't.
The fact that the description makes explicit mention of "normal vision" and "infravision" it is clear that some form of light must be coming from an object for it to be seen by the "eyes". Darkness spell "causes total, impenetrable darkness" (pg 140 of the original PHB), hence a lack of any light; and even "infravision is useless" within its area of effect. So the robe would not be of help against darkness.
We can also compare the description of what the robe can do with the description of the "Detect Invisibility" spell. In "Detect Invisibility" it is clearly stated that the wizard will be able to see invisible objects or beings, and in addition those that are "astral, ethereal, or out of phase", and those that are "hidden or concealed" (page 141 of the original PHB). So we could argue that the descriptions of various magical items and spells are quite complete in the core rulebooks.