Category: O

Describing a tissue that stains readily with osmium tetroxide.  

The condition of complete balance between the movements of the two eyes, such that perfect alignment is maintained even when one eye is covered. This theoretically normal state is in fact rarely seen, since most people have a slight tendency to squint.    

A special form of tomograph that gives a rough scan of the entire jaws.  

Describing or relating to a tissue specimen that stains normally. Having normal color or staining normally.  

A genus of soft ticks, a number of species of which are important in various parts of the world in the transmission of relapsing fever. A genus of ticks (family Argasidae) that infests mammals, including humans. Several species are vectors of the causative agents of disease, including spotted fever, tick fever, Q fever, tularemia, Russian…

A drug used to relieve bronchitis and asthma. It has the same actions and side-effects as isoprenaline.  

A surgical incision into the bony orbit containing the eye. Pain in the testicle. The pain may not be due to a primary condition of the testicle itself: it may be caused by a hernia in the groin, the presence of a stone in the lower ureter, or the presence of a varicocele.  

An instrument for measuring the refraction of the eye. Because the design and use of optometers is very complex, errors of refraction are usually determined using a retinoscope. An instrument used to measure the eye’s refractive power.  

The groove in the top of the orbit that contains the optic nerve and the ophthalmic artery. An opening in the lesser wing of the sphenoid bone. The optic nerve and ophthalmic artery pass through it.  

Either of the paired cup-shaped outgrowths of the embryonic brain that form the retina and iris of the eyes. In the embryo, a double-layered cuplike structure connected to the diencephalon by a tubular optic stalk. It gives rise to the sensory and pigmented layers of the retina.