Bright Eyes

Being able to see in the dark is of great use to any thief or burglar worth his salt and for the less naturally gifted races there are ways to achieve this but they are not without cost.

You spot a thief by his eyes

— Erestean Proverb

Shadow Vision potion

Potions that enhance the darkvision of the user have long been in demand among those who, by inclination or trade, operate in darkness. There are many varieties out there but most have problems, either in terms of their efficacy or in terms of duration. Only one potion known as Shadow Vision is known to circumvents both of these issues, giving full darkvision for an entire night. It is an expensive potion to prepare but the seedy underbelly of the world has plenty of resources to do so and the potion is available for purchase in most major towns and cities if one knows where to look.

Consequences of long term use

However, using Shadow Vision comes with a price that is higher than that paid in gold. The potion works partly by temporarily altering the structure of the cornea adding a reflective layer behind it, similar to that of cats. As the number of uses increases the changes to the cornea become more and more permanent. This leads to the pupil of the eye taking on a silvery appearance when illuminated. At first this change is subtle and hard to spot but if the burglar in question continues using the potion it becomes more and more readily apparent.
The permanency of this change also causes the person to become more and more sensitive to light and at the end stages some resort to either be completely nocturnal or wear deep hoods and sooted glasses during the day.
In many places this condition, known as bright eyes, is considered to be a punishable offence since it can only mean that the person has engaged in illicit activities.

Type

Chemical Compound