The Oculus abilities I am making intentionally vague since I do not want a lot of rules. Situations and circumstances would just make it a mess otherwise to detail. Also it is more in flavor with B/X to make it vague and use imagination over DCs and resistance crap.
In general the abilities scale will be based upon level/HD. A level one can light a torch with Eyes of the Red Dragon, a level ten could conflagrate an inn to the ground. Oculus abilities are probably the closest thing to psionics in the campaign, that is psuedo-magical and in some cases it trumps magical effects. The abilities are essentially at-will to use and concentration to maintain. I will instigate save throws if they are abused or in cases where common sense dictates where it simply is not wise. I would imagine it would not be pleasant to use such an ability and there would be some obvious strain in repeated use.
Trikel, Eyes of the Flowing Sea - Manipulates the forces of motion, in particular liquids. Create a vortex in a lake, over turning a boat, etc.
Enemor, Eyes of the Ebbing Sands - Some mild time manipulation; slowing a incoming balista bolt, speeding up running from a Troll, etc.
Um'Bom, Eyes of Light Unbound - Unburdens the heart, gives strong feelings of compassion, honestly, and repentance when the gaze is focused on a target.
Selyeon, Eyes of Twilight - Causes inner turmoil to surface, reveals ones true nature as in the best and worst of them. More severe effects on heavily lawful or chaotic targets.
Teleth'tun, Eyes of the Red Dragon - Ignite shit on fire of course.
Osteniar, Eyes of Shifting Doom - Varied and indiscriminate curse. Wide array of effects but always malign.
Losburn, Eyes of Western Stars - Instigates bloodlust and heroism to those in view.
Molisine, Eyes of Lurid Dreams - Causes waking dreams in targets, in some cases trapping the victim in their own mind.
Listrim, Eyes of the Trapped Monkey - Copies any viewed action.
Rhianil, Eyes of Passage to the Underworld - User can communicate with unseen spirits and the dead.
Wildenbern, Eye of Blooming - Growth and culmination of reaching ones true potential.
Muru, Eyes of False Wisdom - Distorts beliefs and perceived truths.
Hernok, Eyes of Southern Stars - Instigates strong feelings of direction, motivation, and moral.
Ihlwyn, Eyes of Childish Ways - Incurs the mind of a child in a target. Occasionally permanently.
Hei, Eyes of Mirrors - Can see better in the dark than in normal light, near total awareness in total darkness.
Shinera, Eyes of Comely Truth - All eyes perceive the viewer in a stunning and charmed manner.
Ahbey, Eyes of Summer Storms - Infuses actions with thunder and lightning.
Fhantil, Eyes of Northern Stars - Instigates serenity and benevolence to those in view.
Samel, Eyes of Sullen Thanes - Commands a target to unthinking action.
Bastione, Eyes of Plain Sight - Sees nothing but truth in all things.
Koldrak, Eyes of Thought Unexplained - Inspires a mind permanently to great ingenuity.
Tagdoroane, Eyes of Listless Slumber - Victims fall into stupor, a deep sleep, sometimes for years. Often they awaken with an epiphany.
Jebdul, Eyes of Eastern Stars - Instigates tireless toil among the viewers.
Things will likely shift around as I get it more solidified but this is about what I would use for PC availability. There would be many others of course but most will be detailed as we encounter them. I am tempted to eliminate a race (or more) from having them altogether, adding yet another layer of envy and conflict. Perhaps Halflings since already have a bit of an ambiguous ability as it is.
Most of the well known NPCs who have the Oculus would actually rarely use it (few exceptions of course). When they do it would be a major event and likely something that tales would speak of for months or years. I expect many plots and intrigues would be triggered by such events.