Microphthalmos: Congenital or developmental anomaly in which the eyeballs are abnormally small.Coloboma: Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the fetal intraocular fissure during gestation.Eye, Artificial: A ready-made or custom-made prosthesis of glass or plastic shaped and colored to resemble the anterior portion of a normal eye and used for cosmetic reasons. It is attached to the anterior portion of an orbital implant (ORBITAL IMPLANTS) which is placed in the socket of an enucleated or eviscerated eye. (From Dorland, 28th ed)Anophthalmos: Congenital absence of the eye or eyes.Orbital Diseases: Diseases of the bony orbit and contents except the eyeball.Tissue Expansion: A procedure whereby the body is stimulated to generate extra soft tissue by the application of stretching forces that stimulate new growth of tissue which, over a period of time, results in a 2-dimensional expansion of the tissue. The procedure is used in reconstructive surgery for injuries caused by trauma, burns, or ablative surgery. Various types of TISSUE EXPANSION DEVICES have been developed that exert stretching forces.Tissue Expansion Devices: Devices used to generate extra soft tissue in vivo to be used in surgical reconstructions. They exert stretching forces on the tissue and thus stimulate new growth and result in TISSUE EXPANSION. They are commonly inflatable reservoirs, usually made of silicone, which are implanted under the tissue and gradually inflated. Other tissue expanders exert stretching forces by attaching to outside of the body, for example, vacuum tissue expanders. Once the tissue has grown, the expander is removed and the expanded tissue is used to cover the area being reconstructed.Optic Disk Drusen: Optic disk bodies composed primarily of acid mucopolysaccharides that may produce pseudopapilledema (elevation of the optic disk without associated INTRACRANIAL HYPERTENSION) and visual field deficits. Drusen may also occur in the retina (see RETINAL DRUSEN). (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p355)Cysts: Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Blindness: The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.Eye Abnormalities: Congenital absence of or defects in structures of the eye; may also be hereditary.