ortho-, orth-

(Greek: right, straight, correct, true; designed to correct)

Orthoptera
Primitive winged insects such as cockroaches, locusts, mantises, and crickets.
orthopteran
Any of various insects having leathery fore wings and membranous hind wings and chewing mouth parts.
orthopterous
Relating to the order Orthoptera of primitive winged insects such as cockroaches, locusts, mantises, and crickets.
orthoptic
Designed to improve ocular motility and binocular function.
orthoptics
1. A method of therapy intended to train the eyes to achieve improved muscle balance and binocular vision.
2. The science of correcting defects in binocular vision resulting from defects in optic musculature.
3. The technique of eye exercises, or orthoptic training, for correcting faulty eye coordination affecting binocular vision.
orthoptist
A technician who measures ocular motility and binocular functions and provides therapy to improve them.
orthoptoscope
A device for presenting various images to the two eyes at various angles.
orthorexia nervosa
Instead of having an obsessive desire to lose weight, sufferers from orthorexia apparently have an unhealthy obsession with healthy eating.

In their search for dietary purity, they may become so restrictive about what they eat that they become as dangerously thin as an anorexic; for example, they may over do the avoidance of fatty foods, those with preservatives, and those with salt or sugar; to such a degree that there are very few choices available.

Source of the term orthorexia nervosa

The word, and the identification of the condition, is attributed to a Colorado specialist, Dr. Steven Bratman, who published a book on the subject. He coined orthorexia in 1997 (based on the pattern of anorexia) which comes from Greek orthos, "correct" or "right" plus orexis, "appetite". The word is beginning to appear in the United States and Britain, largely as a result of his book.

Most often, orthorexia is merely a source of psychological distress, not a physical danger. However, emaciation is common among followers of certain health food diets; such as, "raw foodism", and this can at times reach the extremes seen in anorexia nervosa.

Such "anorexic orthorexia" is just as dangerous as anorexia; however, the underlying motivation is quite different. While an anorexic wants to lose weight, an orthorexic wants to feel pure, healthy and natural. Eating disorder specialists may fail to understand this distinction, leading to a disconnect between orthorexic and physician.

—Steven Bratman, M.D;
The Orthorexia Home Page
(inventor of the term "Orthorexia Nervosa")
http://www.orthorexia.com/
orthorhombic
1. Of or relating to a crystalline structure of three mutually perpendicular axes of different lengths.
2. A description of a crystal system that has three axes of different lengths that cross at right angles.
orthoroentgenography
A technique for producing radiographs showing the exact sizes of organs or bones by using a narrow beam of x-rays perpendicular to the plate or film.
orthorrhachic
Denoting a lumbar spine held straight by muscle spasm as opposed to exhibiting the normal lordotic curvature (an abnormal inward, forward, curvature, or sagging, of the spine).
orthoscope
A stereoscope used for evaluation of the relative image size of the two eyes.
orthoscopic
1. Having correct vision.
2. Constructed so as to correct optical distortion; such as, an orthoscopic eyepiece of a telescope.
orthoscopy
Examination of the eyes for visual distortions.
orthosis (s), orthoses (pl)
A device, or appliance, worn on the body to correct, or to prevent, joint deformity, provide support for ambulation (walking), reduce pain, diminish weight-bearing force, or to assist a person's movements.