Refractive Errors 2 Flashcards
What is a floater?
- An opaque spot floating in the vitreous humor
- Can be caused by either retinal or vitreous detachments
A condition in which the crystalline lens of the eye, or its capsule, or both, become opaque, with consequent loss of visual activity
- An ocular disease whose primary characteristic is a sustained increase in intraocular pressure that the eye cannot withstand without damage to its structure or impairment of its function
- loss of peripheral vision
- An ocular disease that is caused by the degeneration of the central portion of the retina, called the macula. The macula is responsible for the central vision in the eye. When it deteriorates, there is loss of central vision and loss of ability to recognize faces, colors or see fine detail
- the ciliary muscle relaxes allowing for a thickening of the crystalline lens
- the eyes converge - the pupils restrict
- its the process in our eyes that allows images to come into focus
- When both eyes work together to bring 2 images into 1.
A refractive error in which the eyeball is too long in relation to focusing power, thus the point of focus for rays of light from distant objects falls in front of the retina.
A refractive error in which the eyeball is too short in relation to the refractive power of the lens. The point of focus for rays of light from distant objects falls behind the retina; accommodating to increase refractive power of the lens is necessary for distance and near vision
What is a latent hyperope?
+/- .75 correction needed, but can accommodate; on its own, the eye will do the work
A refractive error that prevents light from coming to a single focus on the retina because of a different degree of refraction in the various meridians of the eye.
A refractive condition in which rays of light come to 2 focal points is correctable with a cylinder lens
Simple Myopic Astigmatism
The refractive condition where 1 point of focus falls on the retina and the other point of focus falls in front of the retina
Compound Myopic Atigmatism
The refractive error which results in 2 points of focus falling in front of the retina
Simple Hyperopic Astigmatism
The refractive condition where one point of focus falls on the retina and the other point of focus falls behind the retina
Compound Hyperopic Astigmatism
The refractive error which results in two points of focus falling in behind the retina
A refractive condition in which light comes to two points of focus, where one point falls in front of the retina and the other behind the retina
- A refractive condition caused by a cornea which is damaged and irregular so that rays of light come to many focal points on the retina.
- It is not correctable by a cylinder power
A small spring wire attached nasally to a frame to lift a drooping eyelid