Holland Opticians - Holland Opticians


	Refractive states of the eye and definitions of other terminology


	There are many names and definitions for commonly recognised eye conditions which are sometimes misused. Here is a list of the most common conditions and their definitions.

	More

Myopia (Short Sighted)

Near objects are in focus but distant objects are blurred.
The eye is too long for the power of its lens.

Hyperopia (Long Sighted)

Dependent on how hyperopic you are, distant objects may be able to be brought into focus but near objects may not.
The eye is too short for the power of its lens.

Astigmatism

Astigmatism is the distortion within the eye's optical system. Instead of the surfaces being symmetrically round like a football, in one direction they will be more steeply curved like a rugby ball, causing the image you perceive to be distorted, elongated and out of focus.

Presbyopia

This is the term given to the ageing eye. The lens within it becomes less pliable. This makes the ability to bring close work into focus increasingly difficult.

Cataract

The lens within the eye becomes misty and yellow generally due to the ageing process.

Normal Vision

With cataract

Glaucoma

The eye is filled with fluids to maintain its shape and to supply various structures with oxygen. Glaucoma is the term generally given when the pressure within the eye is abnormal, usually too high. Two percent of the population over 40 have glaucoma increasing to fifteen percent of over 80's. Glaucoma can usually be relatively easily controlled - untreated it can lead to blindness. Rarely is any pain or discomfort associated with chronic glaucoma.

Amblyopia (Lazy eye)

This is the name given to the condition when the vision in one eye has not developed properly. Often called a lazy eye. It can be accompanied with strabismus but does not necessarily have to.

Strabismus (Squint)

This is the name given to the condition when the direction of gaze deviates between the two eyes. Often, but not always, associated with an eye being amblyopic.

Age Related Macular Degeneration

AMD occurs when the layer of the retina responsible for nourishing the macula's light sensitive rod and cone cells, and for carrying away waste products, starts to function less effectively as it ages.

Cells in the macula break down, causing loss of sight in the central part of the field of vision but leaving the side vision, known as peripheral vision, unaffected.

Although the breakdown of macular cells may not begin until later life, long-term awareness and preventative measures should begin much earlier.