Retinal enhancements are constucted non-invasively by the use of nanoassemblers. Selected light-receptor cells within the retina are replaced with artificial light detectors. These replacements are capable of operating in a wider range of wavelengths and at greater sensitivity. In some cases the entire surface layer of the retina may be replaced with synthetic photodetectors. Such a total replacement is usually built in several stages so that the original retinal layer may be used to finely calibrate the new detectors.
The enhanced retina is capable of seeing in a visual range that it extended into the infrared, and making use of light as dim as moonlight as if as bright as day. The detectors actually have an almost perfect quantum efficiency, but the image must be processed to eliminate graininess at lower intensities. The detector density in the centre of the visual field is as much as ten times the natural level, so that visual acuity may be boosted by more than a factor of three on command. This is accomplished by expanding the output from the central regions to fill most of the visual field A distorted distribution at the edges of the field is usually introduced stetching from the edges of the magnified region to the edges of the retina. This ensures that some detection of peripheral movement is still possible.
In addition to these major improvements there are many smaller enhancements. The synthetic photodetectors are all sensitive to a range of colours, so that there is no loss of colour vision in dim light. A further option allows increased sensitivity to polarisation, although this is of limited use in most situations. The detectors are engineered to automatically adjust sensitivity to damp sudden flashes that would otherwise lead to temporary blindness.
The replacement detectors are also considerably more robust than the replaced cells In the case of damage the enhancement incorporates an auto-repair system that is capable of repairing a substantial degree of damage such as that caused by brief exposure to lasers. Repairs of this type usually take several hours. More extensive damage would, of course, require retinal or ocular replacement.
The processing layers of the retina are also augmented by artificial neurons that can be used to provide various forms of image processing: maximum-entropy deconvolution, colour balance modification, increased sensitivity to edges and many other options. The neural net is also linked to a nanocomputer that can be used to convert visual data into more conventional formats for recording. All of these features, as well as sensitivity and colour range, are controlled via a pop-up toolkit accessed through an in-built neural interface.
The future of Ad Astra