Encyclopedia - Eye: Encyclopedia Ii - Eye - Acuity
Visual acuity can be measured with several different metrics. Cycles per degree (CPD) measures how much an eye can differentiate one obje...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - Physiology Of Visual Acuity
Visual acuity is defined as the eye's ability to resolve fine details. To achieve this, the eye's optical system has to project a focused...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - Normal Vision
Visual acuity depends upon how accurately light is focused on the retina (mostly the macular region), the integrity of the eye's neural e...   » Read the article

Encyclopedia - Eye: Encyclopedia - Eye
An eye is an organ that detects light. Different kinds of light-sensitive organs are found in a variety of creatures. The simplest eyes d...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Diseases, Disorders, And Age-related Changes
There are many diseases and disorders that may affect the eyes. As the eye ages certain changes occur that can be attributed to solely th...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Anatomy
The structure of the mammalian eye owes itself completely to the task of focusing light onto the retina. All of the individual components...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Varieties Of Eyes
In most vertebrates and some mollusks the eye works by allowing light to enter it and project onto a light-sensitive panel of cells know...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Acuity
Visual acuity can be measured with several different metrics. Cycles per degree (CPD) measures how much an eye can differentiate one obje...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Evolution Of Eyes
How a complex structure like the projecting eye could have evolved is often said to be a difficult question for the theory of evolution. ...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Cytology
The retina contains two forms of photosensitive cells - rods and cones. Though structurally and metabolically similar, their function is ...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Adnexa And Related Parts
Eye - The orbit. In many species, the eyes are inset in the portion of the skull known as the orbits or eyesockets. This placement of t...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Eye Movement
Animals with compound eyes have a wide field of vision, allowing them to look in many directions. To see more, they have to move their en...   » Read the article

Encyclopedia - Eye: Encyclopedia - Eye
An eye is an organ that detects light. Different kinds of light-sensitive organs are found in a variety of creatures. The simplest eyes d...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia - Visual Acuity
Visual acuity (VA) is one of many components of the visual perception sense and is defined as the eye's ability to resolve fine details. ...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - Measurement
Visual acuity is typically measured monocularly rather than binocularly with the aid of an optotype chart for distant vision, an optotype...   » Read the article

Encyclopedia - Eye Examination: Encyclopedia Ii - Eye Examination - Setting
Ideally, the eye examination consists of an external examination, followed by specific tests for visual acuity, pupil function, extraocul...   » Read the article

Encyclopedia - Eye Examination: Encyclopedia Ii - Eye Examination - Comprehensive Eye Examination
Eye examination - Case history. Eye examination - Entrance tests. External examination Visual acuity Amplitude of accommodation Colo...   » Read the article

Encyclopedia - Visual Loss: Encyclopedia - Visual Loss
Visual loss results in the absence of vision where it existed before, which can happen either acutely (i.e. abruptly) or chronically (i.e...   » Read the article

Encyclopedia - Blindness: Encyclopedia - Blindness
Blindness can be defined physiologically as the condition of lacking visual perception. The definition as it applies to people thus lega...   » Read the article

Encyclopedia - Eye Examination: Encyclopedia Ii - Eye Examination - Basic Examination
Eye examination - External examination. External examination of eyes consists of inspection of the eyelids, surrounding tissues and pal...   » Read the article

Encyclopedia - Red Eye Medicine: Encyclopedia Ii - Red Eye Medicine - Investigation
Some signs and symptoms of red eye represent warnings that the underlying cause is serious and requires immediate attention. The person c...   » Read the article

Encyclopedia - Red Eye Medicine: Encyclopedia Ii - Red Eye Medicine - Important Warning Symptoms
There are three main danger symptoms in a red eye: reduced visual acuity, severe ocular pain, and photophobia (light sensitivity). Red e...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - History
In 1843 Kuechler, a German ophthalmologist, developed a set of three charts, but his work was almost completely forgotten. In 1854 Jaeger...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - Visual Acuity Expression
Visual acuity is often measured according to the size of letters viewed on a Snellen chart or the size of other symbols, such as Landolt ...   » Read the article

Encyclopedia - Visual Acuity: Encyclopedia Ii - Visual Acuity - Measurement Considerations
Visual acuity measurement involves more than being able to see the optotypes. The patient should be cooperative, understand the optotypes...   » Read the article

Encyclopedia - Visual Loss: Encyclopedia Ii - Visual Loss - Acute Visual Loss
Acute visual loss may be dramatic in presentation, and is almost always alarming to the person experiencing the loss. It may be caused by...   » Read the article

Encyclopedia - Diabetic Retinopathy: Encyclopedia Ii - Diabetic Retinopathy - Diagnosis
Diabetic retinopathy is detected during an eye examination that includes: Visual acuity test: This test uses an eye chart to measure how...   » Read the article

Encyclopedia - Photorefractive Keratectomy: Encyclopedia Ii - Photorefractive Keratectomy - Possible Complications
Some complications of PRK include: Long healing period Pain Glare, halos, or starburst Aberrations Under- or over-correction Recurrence ...   » Read the article

Encyclopedia - Anterior Ischemic Optic Neuropathy: Encyclopedia Ii - Anterior Ischemic Optic Neuropathy - Symptoms And Diagnosis
AION typically presents suddenly and upon awakening. The patient notes seeing poorly in one eye. Vision in that eye is obscured by a dark...   » Read the article

Encyclopedia - Eye Chart: Encyclopedia Ii - Eye Chart - Procedure
Charts usually display several rows of optotypes (test symbols), each row in a different size. The person is asked to identify the optoty...   » Read the article

Encyclopedia - Temporal Arteritis: Encyclopedia Ii - Temporal Arteritis - Symptoms
It is more common in females and after 50 years of age. Below this age it is extremely rare. Patients present with: fever headache tende...   » Read the article

Encyclopedia - Photorefractive Keratectomy: Encyclopedia Ii - Photorefractive Keratectomy - Lasek Versus Lasik
LASEK is a procedure that permanently changes the shape of the cornea using an excimer laser to ablate a small amount of tissue from the ...   » Read the article

Encyclopedia - Optic Nerve Hypoplasia: Encyclopedia Ii - Optic Nerve Hypoplasia - Symptoms
Optic nerve hypoplasia can appear in one or both eyes, causing anywhere from a mild to serious visual impairment in the form of decreased...   » Read the article

Encyclopedia - Lasik: Encyclopedia Ii - Lasik - Complications
Although relatively uncommon, complications due to LASIK do occur. The following are some of the more frequently reported complications o...   » Read the article

Encyclopedia - Lasik: Encyclopedia Ii - Lasik - Complications
Although relatively uncommon, complications due to LASIK do occur. The following are some of the more frequently reported complications o...   » Read the article

Encyclopedia - Bear: Encyclopedia Ii - Bear - Physical Attributes
Common characteristics of bears include a short tail, excellent senses of smell and hearing, five un-retractable claws, and long, dense, ...   » Read the article

Encyclopedia - Bear: Encyclopedia Ii - Bear - Physical Attributes
Common characteristics of bears include a short tail, excellent senses of smell and hearing, five un-retractable claws, and long, dense, ...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Evolution Of Eyes
How a complex structure like the projecting eye could have evolved is often said to be a difficult question for the theory of evolution. ...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Cytology
The retina contains two forms of photosensitive cells - rods and cones. Though structurally and metabolically similar, their function is ...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Adnexa And Related Parts
Eye - The orbit. In many species, the eyes are inset in the portion of the skull known as the orbits or eyesockets. This placement of t...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Adnexa And Related Parts
Eye - The orbit. In many species, the eyes are inset in the portion of the skull known as the orbits or eyesockets. This placement of t...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Varieties Of Eyes
In most vertebrates and some mollusks the eye works by allowing light to enter it and project onto a light-sensitive panel of cells know...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Varieties Of Eyes
In most vertebrates and some mollusks the eye works by allowing light to enter it and project onto a light-sensitive panel of cells known...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Diseases Disorders And Age-related Changes
There are many diseases and disorders that may affect the eyes. As the eye ages certain changes occur that can be attributed to solely th...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Diseases Disorders And Age-related Changes
Main articles: List of eye diseases and disorders and Ocular manifestations of systemic disease There are many diseases and disorders tha...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Anatomy
The structure of the mammalian eye owes itself completely to the task of focusing light onto the retina. All of the individual components...   » Read the article

Encyclopedia - Eye: Encyclopedia Ii - Eye - Eye Movement
Animals with compound eyes have a wide field of vision, allowing them to look in many directions. To see more, they have to move their en...   » Read the article