Introduction The cranium protects the brain and provides scaffolding for facial structures. During primate evolution, the orbits were enlarged and reoriented towards the front of the face. This, along with…

The lens is a remarkably specialized epithelial tissue that is responsible for fine-tuning the image that is projected on the retina. To perform this function it must be transparent, have…

Introduction The vasculature of both the retina and brain can autoregulate, meaning that blood flow is altered in response to neuronal activity. This tight coupling between neuronal activity and blood…

Introduction The ocular circulation is unique and complex due to the presence of two distinct vascular systems, namely the retinal and uveal systems. The part of this circulation, the one…

Introduction The retinal pigment epithelium (RPE) is a monolayer of pigmented cells located between the light-sensitive photoreceptor outer segments and the fenestrated endothelium of the choriocapillaris. On both sides, specialized…

Introduction The vitreous body makes up approximately 80% of the volume of the eye and thus is the largest single structure of the eye ( Fig. 6.1 ). In the…

In the healthy eye, flow of aqueous humor against resistance generates an intraocular pressure (IOP) of approximately 15 mmHg, necessary for the proper shape and optical properties of the globe. The…

The extraocular muscles (EOM) are found within the bony orbit. They function in conjugate eye movements, maintenance of primary gaze position, and motor fusion – maintaining corresponding visual elements within…

Introduction Three fundamental visual sensory-motor tasks The neural control of eye movements is organized to optimize performance of three general perceptual tasks. One task is to resolve the visual field…

Eye motility In principle the eyeball, like any rigid object, has six degrees of freedom: three for rotation, and three for translation. The adult human eyeball is about 24–25mm in…