Torn out of Vecnagon's head and sold as a luck charm, Vecnagon cursed it before he made his escape from his would be butcher.

Vecnagon's Obscure Eye had already been traded away before Vecnagon could retrieve it. Hence it has since been sold, lost, and found and is still believed to be a powerful luck charm. In reality, NOT! It will grant it's user powers indeed. But at an extremely high price.

Curse: Oooooo. Those that know of this item. Want it. Who wants good luck more than the selfish and greedy. That includes NPC's and PC's alike. Character's honestly noble in heart (lawful good doesn't mean they're "pure" of heart) or find old ugly things too grotesque to get near will be unaffected by this. Character's with child like mentality it's a give or take. 50/50 shot they will just ignore it. But those looking to gain...   Power, advantage, wealth, simply more. They will be susceptible. (So if a PC has been having a rough time and their "will" is somewhat diminished for exmaple) DMs you know your players and what their PC's are supposed to be like, so who is up to you. A Wisdom saving throw at DC 18 must be made. If the NPC or PC has a Wisdom or Intelligence of 20, they have advantage on this save (something in the back of their head is telling them NOOOOO). It's kind of like the draw that really really REALLY famous ring has. Then of course you have those PCs who will just take it. Use it. No dice rolls needed. Of course, there are those who are not knowledged enough as to confuse this item with another similar item.

Curse: Diabolical Debacle.  THE CURSE IS BASED ON THE NECROMANTIC SPELL CONTAGION Legacy   Once this curse is under way there is no stopping it. On the third day after attuning with Vecnagon's Obscure Eye, you must make a Constitution save DC 18. If your Intelligence is below 20, you make this save with disadvantage. Success on the save means nothing happens. But now a constitution save must be made once every day/dawn until you fail the save. On a failed constitution save you suffer a terrible fate.

You suffer the effects of the Diabolical Debacle. Over the next 8 days you will suffer much pain and anguish. At the end of the 8th day you die. If the eye is not attuned with someone in the next 3 days after your death, it will vanish. It will reappear anywhere near to (within a mile) or within one of the countless Hollow on the Hills that exist. The effects of the Diabolical Debacle curse are cumulative. So by the 6th day, the user will have all 6 ailments simultaneously. 

 The user will suffer as follows :

• Day one:  Blinding Sickness. Pain grips the your mind, and your eyes turn milky white. You have disadvantage on Wisdom checks and Wisdom saving throws and are blinded.
• Day two:  Filth Fever. A raging fever sweeps through your body. You have disadvantage on Strength checks, Strength saving throws, and attack rolls that use Strength.
• Day three: Flesh Rot. Your flesh decays. You have disadvantage on Charisma checks and vulnerability to all damage.
• Day four: Mindfire. Your mind becomes feverish. You have disadvantage on Intelligence checks and Intelligence saving throws, and you behave as if under the effects of the confusion spell during combat.
• Day five: Seizure. You are overcome with shaking. You have disadvantage on Dexterity checks, Dexterity saving throws, and attack rolls that use Dexterity.
• Day six: Slimy Doom. You begin to bleed uncontrollably. You have disadvantage on Constitution checks and Constitution saving throws. In addition, whenever you take damage, you are stunned until the end of its next turn.
• Day eight: Death. Self explanatory. No?

No. This curse does not turn it's victims into undead. Under no circumstance. At all. Except for Vecnagon himself, this curse was made to make any and all humanoids who would dare use his eye suffer and die. Period.  No "cure," "protection," or "remove" spell will end this curse. The only way to end this curse is that the you physically remove Vecnagon's Obscure Eye  from your own head. Vecnagon's Obscure Eye will not leave without a fight. Every strand of it's muscles and nerve endings will attempt to hold  it in place. It will have to be torn out...not cut out. Despite your weakened state, you still have a chance to remove it. You will need to make a Strength check with a DC of 18. This tug of war will  leave your left side of the face scarred from both physical and nerve damage. Both over and under the flesh. ( Think ripped torn pock marked eye socket with drooping facial muscles ) The damage done by this is permanent. New wounds can be healed but not these wounds. The new appearance is forever. And no; your face does not look like a zombie face. Just a damaged eye socket with a facial disfigurement. (There are plenty of people alive today that have an empty eye socket. You can probably find pics online. Scary looking enough) Your flesh is not hanging down by your elbows. It's just drooping (like a serious case of Bell's Palsy).

If the removal attempt is successful the curse ends immediately and Vecnagon's Obscure Eye also immediately vanishes. If the attempt is failed you may continue to make other attempts. It's up to the DM  to decide if you need a long or short rest between attempts.  Also the amount of facial damage can be determined by how many attempts are made. . Even how much the face droops on that side can be determined this way. Remember there is ALWAYS damage to that side of the face. How much is up to the DM (NOTE: You will always have an empty eye socket now, with or without eyelids. Glass eye time). It will also take 1d3 days to recover completely from the effects of the illnesses suffered.

 Curse: What wuz dat. No one knows of the curse on this item. It is generally believed that this is a powerful luck charm. That it brings benefits to it's user. In addition no one who has dealt with this item, and not died, remembers the curse of this item. The memory of it fades with their "healing." They remember having it. Using it. Then remembering someone stole it from them. Maybe something about a dog. That's it. There are no details to this memory. And when witnesses (normally fellow party members) tell the story, most people tend to believe that the party did that damage to their party member in a fight over treasure.

NOTE: Remember even though your blindness prevents the use of most of the abilities gained through Vecnagon's Obscure Eye, you are still able to use Foresight.

Now that all the good stuff is out of the way:

• Your alignment changes to neutral evil.
• You have Darkvision with a range of 30 feet.
• You may cast True Seeing: 1 action, Self, V. S., 1 hour, range 24 feet. No specific level or class  or material components are required. You innately know how to cast the spell.
• If Vecnagon is using the eye he does not cast True Seeing. Instead his truesight  now has a range of 120 feet.
• You can use an action to gain Foresight.  Whenever you use this action again before taking a long rest, you must succeed on a DC 18 Constitution saving throw or gain one level of exhaustion.
• The eye has 8 charges. You can use an action and expend 1 or more charges to cast one of the following spells (save DC 18) from it:  Blight (3 charges), Blindness/Deafness (1 charge),  Dominate Beast (4 charges), Eyebite (4 charges), Ray of Enfeeblement (3 charges). The eye regains 1d4 + 4 expended charges daily at dawn.

Properties of the Eye and Foot. If you are attuned to both the foot and eye, you gain the following additional benefits:

• You are immune to poison and paralysis.
• Using the eye's Foresight never causes you to suffer exhaustion.
• Your senses are heightened and unless you are incapacitated, you can't be surprised.
• If you start your turn with at least 1 hit point, you regain 1d8 hit points.
• If Vecnagon is the creature attuned to the eye and foot, Circle of Death now costs 3 charges. The somatic of Stomping the 'foot' is still required. Hey it looks/sounds cool.
• Each time you cast a spell using the eye and/or foot, they cast the Suggestion spell on you (save DC 18), demanding that you commit an evil act. They might have a specific act in mind or leave it up to you. The 'specific act' will be decided by the DM.
• If Vecnagon is the creature attuned to the Eye and Foot there is no Suggestion spell cast upon him. As he is already planning or committing an evil act.
• If you are surrounded by humanoid enemies, you may use an action to cast the spell A Plethora of Poultry.  3rd Level   1 Action   30 Feet   1 Hour   Conjuration   Summoning.  The immediate area begins to rumble and then bursting forth from the ground in a spray of feathers, and whatever else is on the ground,  a multitude of Vecnagon's Flock of Zombie Chickens in the chosen location. The summoned creatures are friendly to you and your companions. Roll initiative for the summoned creatures as a group, which has its own turns. They obey any verbal commands that you issue to them (no action required by you). If you don't issue any commands to them, they defend themselves from hostile creatures, but otherwise take no actions. All normal rules for Vecnagon's Flock of Zombie Chickens apply.
• If Vecnagon is the creature casting A Plethora of Poultry, it costs no action to cast.
• You can use an action to cast one Wish. This ability can't be used again until 38 days have passed.

 Destroying the Eye.  Any attempt to destroy the eye seems to work. It goes out in a blaze of unholy glory or just fades away. In truth the artifact reappears in or near (within a mile)  one of Vecnagon's many Hollow on the HIlls, where it waits to be rediscovered by anyone.

Notes: An Eye for an Eye. With your own hand you must gouge out your left eye and replace it with Vecnagon's Obscure Eye. Vecnagon's Obscure Eye must always be placed in the left eye socket. The nerve endings, muscles and blood vessels of the eye crack and creek to reach for and pulls itself into the eye socket. The sounds of wet shlopping movement can be heard by the new owner of the eye and those near him/her/it as this mummified eye pulls itself into position and fits itself into place. An extremely raw and painful occurrence. Once in place the eye comes "alive" with an extremely bloodshot combination of red and sickly green hues with a large dark pupil. Like that of a rabbit or similar rodent. A price must always be paid to use Vecnagon's Obscure Eye. If your left eye is missing before you intend to use Vecnagon's Obscure Eye, you must gouge out your right eye. If for whatever reason there is no left side eye socket, Vecnagaon's Obscure Eye will make one. The one who wishes to use this eye will innately know the cost for it. Vecnagon's Obscure Eye will not "work" for someone with no physical eyes to trade for it. A beholder would have to choose an eyestalk on it's left side., An Eye for an Eye., Foreknowledge, Cursed, Headwear, Eyewear, Symbiotic