There are a number of major steps that are required prior to the utilisation of these technologies in a clinical setting. This phase of the Proposal will aim to validate and calibrate the new technologies, explore the signal-to-noise ratio of RBF and oxygen saturation parameters, generate values to define the impact of absorption, morphological fundus variation and pre-retinal autofluorescence on oxygen saturation imaging and will establish a database of healthy control imaging values for both new technologies and the reproducibility of those measurements. Note: Sample size calculations have been conducted for all aspects of this phase of the protocol, based upon our extensive retinal vascular reactivity work. We will build and develop unique quantitative imaging technologies to that will permit us to explore the physiology of retinal and choroidal perfusion and vascular regulation, and retinal oxygenation.