Optometry Terms: M-P
Macula- a small, sensitive part of the retina which is responsible for central vision.
Myopia, nearsightedness- eyesight abnormality in which distant objects are unclear, as a result of the images being focused in front of the retina instead of on it.
Neovascularization (ocular)- abnormal or extreme formation of blood vessels in the eye.
Nystagmus- involuntary movement of the eyes.
Ophthalmologist- a medical doctor who specializes in diagnosis and treatment of eye diseases.
Ophthalmoscope- a medical tool used in examining the retina.
Optic disc, optic nerve head- blind spot, the point where the optic nerve passes into the retina.
Optic nerve- a cranial nerve that emerges from the retina and transfers visual information to the brain.
Orthoptics- treatment of binocular vision defects in nonsurgical ways such as exercises.
Perimetry- the identification of the visual field limits.
Peripheral vision – This is a part of vision that exists beyond the center of a person’s gaze. Peripheral vision is broken up into three general points. “Far peripheral” vision is the area farthest from a person’s center of gaze and is at the edges of the field of view. “Mid-peripheral” is in the middle of the field of view. “Near-peripheral”, or otherwise known as “para-central” vision, lies adjacent to the center of gaze.
Phacoemulsification - This refers to modern cataract surgery. The surgery requires that the eye’s internal lens be emulsified with an ultrasonic hand piece and aspirated from the eye. These aspirated fluids are then replaced with use of a balanced salt solution. This maintains the anterior chamber, as well as making sure the hand piece remains cool.
Photophobia – This refers to an extreme sensitivity to light and the aversion to sunlight or well-lit places. Photophobia is neither a morbid fear nor phobia, rather it is discomfort or pain to the eyes caused by exposure to light.
Pinguecula - This a common type of conjunctival degeneration in the eye.
Presbyopia - A condition in which the eye performs at a progressively lowered capability to be able to focus on objects that are near as one ages.
PRK (photorefractive keratectomy)- This is a laser eye surgery procedure intended to correct a person’s vision and in doing so reduce the patient’s dependency on glasses or contact lenses.
Progressive Addition Lens (PAL)- are corrective eyeglass lenses characterized by a gradual increase in lens power that is added to the wearer’s correction additional refractive errors.
Pterygium – Also known as Surfer’s Eye, Pterygium most usually refers to conjunctiva , which is a benign growth. A pterygium usually forms from the nasal side of the sclera. The common thinking is that is caused by exposure to ultraviolet-light, low humidity, and dust.
Ptosis – Commonly refers to a droopy eyelid.
Pupil – The pupil is a black hole at the center of the eye whose function is to let light hit the retina.