Bledsoe's disease was a virus that spread through both airborne transmission and direct physical interaction. It was common knowledge that squills acted as vectors for the disease.
The disease manifested in a variety of forms, with each strain triggering distinct reactions. A typical progression of Bledsoe's involved a burning sensation on the skin, which was followed by a gradual change in the color of the eyes. The discoloration eventually coalesced into a starfield pattern. Despite its unusual appearance, the pattern had absolutely no effect whatsoever on the vision of those infected. Dizziness was also a symptom that presented itself in the later phases of the illness.
Around 0 ABY, a specific strain of the virus was engineered by Dr. Kaaldar, a highly skilled Imperial scientist, and an epidemic was deliberately initiated. The underlying objective was twofold: first, to destabilize the social structures of discontented worlds, and second, to discover the hidden locations of Rebel Alliance bases. The virus was genetically modified to embed information that would influence the resulting symptoms. One particular symptom, known as the "window effect," was specifically designed to act as a covert means of transmitting star charts. By examining the eyes of infected individuals, Imperial scientists could use an ocular printer to decipher a star map, thereby revealing the locations of Rebel bases for targeting by the Imperial Fleet.
Imperial forces maintained surveillance for outbreaks of Bledsoe's disease, utilizing the eye discoloration as a discreet method of communication and strategic planning. However, this effect faded quickly after death. This was demonstrated by instances where stormtroopers were unable to glean any information from the eyes of Jawas who had been dead for some time when their sandcrawler was discovered.
To ensure the spread of the disease, Imperial forces inoculated several squills with the Bledsoe's virus. Squills possessed a natural immunity to the disease, which made them ideal carriers. These squills were then placed inside transport containers and launched toward planets suspected of harboring Rebel sympathizers, including Tay'ah'loo, Ogem, and Tatooine. While the infection of the first two planets proceeded as planned, resulting in the discovery and destruction of the Rebel Outpost on Kholes by the Empire soon after, the situation on Tatooine took an unexpected turn when a group of Jawas inadvertently intercepted the transport capsule. Furthermore, the Rebel Alliance became concerned enough that they eventually tasked Luke Skywalker with undertaking a mission to Tatooine to investigate the matter, much to his reluctance.
A minor alteration was made to the "stars in the eyes" visual effect between the original release of Tatooine Sojourn in 1979 and the subsequently republished color version. In the original version, after Luke Skywalker contracted Bledsoe's, a ringed planetary object was visible in the lower right section of his "star eye." This planetary object was removed in the later colored versions.