Ophthalmic Science Fiction, Hold the Fiction.

A Brief History of the Retinal Scan 

     

     Thanks to innovations in ophthalmic technology, identification by retinal scan has evolved from a hypothetical possibility to a readily available, highly accurate tool. It still holds much sway in today's science fiction portrayals of advanced technology.

1886

Alphonse Bertillon's method was overtaken by fingerprinting, but the use of his "mugshot" remains. 1893.

     The concept of eye-recognition surfaced in 1886, when Alphonse Bertillon suggested that the eyes could be used to identify criminals. Granted, he imagined a system of identification based on the details in the iris, rather than the retina. Bertillon was a criminologist who recommended that the police record a long list of physical measurements in order to positively identify repeat offenders. Many of his practices were adopted for a time, but his only surviving technique is the photographing of individuals under arrest, known today as the mug shot.

1935

     The first scientifically supported idea for retinal identification was published in the New York State Journal of Medicine in 1935. The basic idea was to use the unique pattern of blood vessels in the retina to identify an individual. The technology for a device that could realistically perform this task would not emerge for decades. 

Popular Culture

        

Batman and Robin with the retinal-scan-equipped Bat Mobile
in the 1960s.

The relative obscurity and "high tech" nature of retinal scans means that they are a frequent device in fiction - to suggest that an area has been particularly strongly secured against intrusion, to indicate that technology has advanced beyond what we regularly see today, even to pronounce a dehumanization of technological advancement.

Captain Kirk debuts retinal scanning technology in 1982.

         Retinal scanners are mentioned for years before the first viable model was designed in 1975. Batman and Robin, for example,  use a retinal scanner in a 1966 film to identify the Penguin. In 1976, full time efforts were made to complete a

Congratulations, Jim. You are who you claim to be. 

scanning device, and in 1978 it was patented, with a commercial model following in 1981. Captain Kirk introduced the device in motion pictures in 1982. 

More instances of eye scanning in contemporary media.

How it Works

       Each person’s retina is unique because the structure of blood vessels is so complex. Not even identical twins share the same pattern. Though the patterns in the retina can be altered by certain eye

Image of the veins of a normal human retina. 

diseases, they typically stay about the same from birth until death.  Apart from DNA, retinal recognition is the most precise form of identification currently available, with an error rate of 1 in ten million.  

A retinal scan works by casting a beam of low-energy infrared light into a person’s eye as they look through the scanner's eyepiece. This beam of light traces a standardized path on the retina. Because retinal blood vessels absorb light more readily than the surrounding tissue, the amount of reflection varies during the scan. The pattern of variations is digitized and stored in a database. An algorithm has to be employed to analyze each image in a video stream that receives the information from a cast beam of light.

Applications

     Retinal scanners are typically used for authentication and identification purposes. They have been utilized by several government agencies including the FBI, CIA, and NASA. However, in recent years, retinal scanning has become more commercially popular. Retinal scanning has been used in prisons, for ATM identity verification and the prevention of welfare fraud.

          Retinal scanning also has medical applications. Communicable illnesses such as AIDS, syphilis, malaria, chicken pox and Lyme disease as well as hereditary diseases like leukemia, lymphoma, and sickle cell anemia affect the eyes., so scanning for retinal abnormalities can provide early awareness chronic illnesses.

       Very recently, smartphone apps like Peek use this technology in rural parts of the world where eye care is difficult to come by. Minimal training is required to operate Peek, as the information is gathered and then sent to experts around the world for diagnosis.

Impediments

       There are downsides to retinal scanning for the purposes of identification. Certain conditions like cataracts can impede light from entering the eye, thus obscuring retinal information. Accuracy can also be compromised by astigmatism. Scanning procedure is perceived by some as invasive, likely due to its presence in science-fiction stories where technology has gone a bit too far. The cost for reliable equipment also makes it too obscure for some potential users to employ practically.