Visual disorders and retinal development
Our vision does not depend solely on the simple detection of different patterns and wavelengths (colours) of light. Our eyes sense the environment around us and our brain interprets this information to make judgements about the nature of objects, their position in space, movement, significance and familiarity to us.
The human eye is designed to focus light onto the retina. The light-sensitive cells of the retina are rod photoreceptors, responsible for night vision, and cone photoreceptors, responsible for colour vision and reading. These photoreceptors convey information to nerve cells in the retina that are much like nerve cells in the rest of the brain. Regarded as part of our central nervous systems, the neural circuitry of the retina provides some insight into how the brain works. The image shows light sensitive photoreceptor cells in the mammalian retina (blue), different types of nerve cells that connect with the photoreceptors and process colour and luminance information (red, green, yellow) and the organisation of the synaptic layers in the retina (red lamination).
The Human Genome Project has informed scientists about the DNA sequences that instruct the developing embryo to form a normal visual system. We also know about some of the differences between individuals in their DNA code that influence normal variations, such as iris colour and refractive error (short or long-sightedness). An individual’s DNA can now be sequenced to work out their future risk of eye disease or the cause of an inherited visual disorder. BVI researchers led by Denize Atan are investigating the identity and function of genes that influence the normal development of our eyes and visual system, and what happens to our vision when these genes are faulty. This research is particularly focused on understanding the wiring of neural circuitry within the retina and what this can tell us about the rest of the brain. By taking a molecular approach and looking inside cells and our DNA to identify the processes that influence our vision of the world, this research hopes to further our understanding of retinal development.