| A Short Course in Evaluation of Pupil Sizes |
In the case of brain injury (concussion, for example) the pupils sometimes give us information about where and how severely the brain might be effected.
Normal Responses to Light and dark
There are two main pupillary responses to light, the Direct and Indirect.
When a light is shined into the eye, its strongest reaction is from the Direct Response, and is just what you expect: the pupil should get smaller when a light is shined directly into it. The In...
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| Accommodative Esotropia |
When you were young, your mother probably told you to stop crossing your eyes because if didn’t, they might get stuck that way. While there is no truth at all to this myth, it is possible that infants and young children can develop misaligned eyes, a condition that is called strabismus.
Figure 1
There are several types of strabismus. (See figure 1) If one eye turns inward it is called esotropia, while if an eye turns outward it is called exotropia. Strabismus c...
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| Adults Failing When It Comes To Eye Care Knowledge |
44% of parents are not aware that behavioral problems can be an indication that a child s vision is impaired.
American Optometric Association s first American Eye-Q(TM) survey finds parents lack important knowledge about eye health and vision care.
As millions of students nationwide head back to school, the American Optometric Association s first American Eye-Q(TM) survey finds parents lack important knowledge about eye health and vision care. While millions of children will start school ...
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| Age-Related Macular Degeneration (AMD) & the Aging Population |
As the baby boomer cohort approaches retirement age, vision loss and illness among the elderly will reach near-crisis proportions. Aging is the greatest risk factor for vision loss, and the leading cause of that loss is age-related macular degeneration (AMD), a condition that causes irreversible damage to vision.
At the back of the eye, there is a thin layer of light-sensitive tissue called the retina. Light is focused behind the retina onto a small spot called the macula. The macula then proce...
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| Allergies |
Now that the summer is upon us we can finally enjoy the many outdoor activities of summer. For many Essex County residents this is also a time where seasonal allergies can cause problems with our eyes and respiratory systems.
Seasonal allergies are caused by specific allergens such as ragweed grass or tree pollen. When these allergens come in contact with your body they are considered foreign particles. The allergens bind themselves to mast cells which are loaded with histamine. In respon...
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| Am I a Candidate for Laser Surgery? |
Am I a Candidate for Laser Surgery?
It is critical that a potential laser vision correction candidate has obtained a stable prescription for at least one year.
We believe that there are many things you should consider before determining whether laser vision correction is right for you. Laser vision correction is a surgical procedureand should be approached in the same manner as any other surgery you may have; questions should be asked and research should b...
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| Amblyopia (Lazy Eye) |
Amblyopia (Lazy Eye)
It is estimated that three percent of children under six have some form of amblyopia. Young eyes need proper visual stimulation in order for mature vision to develop. For this to happen both eyes need clear images of the world to focus on the retina and then be transmitted to the visual cortex of the brain. Amblyopia also known as “lazy eye” is a condition that occurs when vision in one eye is reduced because the eye and the brain are not working together prop...
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| Amblyopia and Lazy Eye |
It is estimated that about three percent of children less than six years of age have some form of amblyopia, which causes decreased vision in the affected eye. Also known as Lazy Eye, amblyopia is considered to be the most common form of vision loss in childhood.
Figure 1
To understand amblyopia and its causes, it is useful to think of vision as something that occurs in the brain, not just in the eye. Light enters the eye through the pupil and is focused onto the retina. ...
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| AMD |
AMD occurs when the macula, the area at the back of the retina that produces the sharpest vision, deteriorates over time. Women younger than age 75 years who eat diets rich in the yellow plant pigments lutein and zeaxanthin may have a reduced risk of developing AMD Women younger than age 75 years who eat diets rich in the yellow plant pigments lutein and zeaxanthin may have a reduced risk of developing the eye disease age-related macular degeneration, according to a report in the August issue of...
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| AMD & the Aging Population |
As the baby boomer cohort approaches retirement age vision loss and illness among the elderly will reach near-crisis proportions. Aging is the greatest risk factor for vision loss and the leading cause of that loss is age-related macular degeneration (AMD) a condition that causes irreversible damage to vision.
At the back of the eye there is a thin layer of light-sensitive tissue called the retina. Light is focused behind the retina onto a small spot called the macula. The macula then processes...
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| AMD Discovery |
AMD Discovery: New Hope for Treatment of Vision Loss "This discovery brings us one step closer to treating dry AMD which could significantly improve the quality of life of seniors who are most affected by this eye disease"
Scientists have won a major battle in the fight against age-related macular degeneration or AMD a blinding eye disease that affects millions of people. An international team led by researchers at Sainte-Justine Hospital and the Université de Montréal has identif...
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| AMD Protection May Come From Select Veggies |
AMD occurs when the macula the area at the back of the retina that produces the sharpest vision deteriorates over time. Women younger than age 75 years who eat diets rich in the yellow plant pigments lutein and zeaxanthin may have a reduced risk of developing AMD Women younger than age 75 years who eat diets rich in the yellow plant pigments lutein and zeaxanthin may have a reduced risk of developing the eye disease age-related macular degeneration according to a report in the August issue of Ar...
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| AMD: Healthy Eating is Essential for Saving Your Vision |
Introduction
Age-related Macular Degeneration (AMD) is one of the most common causes of irreversible vision loss in developed countries. Estimates of how many people are affected vary considerably, but the percentage of the population with it increases with age. While only 2% of people aged 50 to 59 have the disease, the incidence rises to nearly 30% by the age of 75 years. Therefore, the greatest risk factor for developing this condition is age. Please see our article titl...
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| AMD: Known Risk Factors |
Age-Related Macular Degeneration (AMD) is one of the leading causes of blindness in Canada and the US. AMD is an irreversible type of progressive degeneration of the area of the retina that is most important for sharp, clear vision. While AMD is not curable, it is possible to reduce the risk of developing this devastating condition and slowing down the rate of progression.
The photograph shows deposits in the retina (light colored spots) and leaking blood vessels (red blotche...
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| AMD: The Role of Genetic Testing in the Use of Ocular Multivitamin Supplements |
Vision Preservation and Your DNA
Age-Related Macular Degeneration (AMD) is one of the leading causes of blindness in North America, due to its progressive disease course and its devastating effects on central vision loss.
AMD is classified into two main categories based on damage to the macular area of the retina as dry AMD, seen in patients with early signs of deposits in the retina, and wet AMD, a later, more aggressive stage of the disease characterized by incre...
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| AMD: The Sneak Thief of Vision |
Age-Related Macular Degeneration (AMD) is considered to be the leading cause of functional vision loss in people over the age of 55 in the western world. Estimates of how many people are affected vary considerably, but the percentage of the population with it increases with age. While only 2% of people aged 50 to 59 have the disease, the incidence rises to nearly 30% by the age of 75 years. Therefore, the greatest risk factor for developing this condition is age.
There is important new inf...
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| Amsler Grid Instructions |
People who have been diagnosed with Age-Related Macular Degeneration (ARMD or AMD) are often given a card or sheet of paper printed with a grid of squares and a dot in the center. This is known as an Amsler Grid; this is a handy device designed for monitoring your own vision at home.
AMD can progress slowly, or quickly, so it is a good idea to monitor your own vision at home for changes that may happen between vision checkups in your eyecare practitioner’s office.
Follow th...
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| Anatomy of the Eye: A Quick Overview |
Vision is widely considered to be the most important of our five senses. Knowing about the basic structures of the eye helps people understand where an eye problem may be located and what is normal or not normal.
Basic knowledge in this area can also help decide if a patient needs to be seen by an eyecare practitioner and whether the problem may be need to be seen at once as an emergency, or how urgent it may be. An ocular emergency indicates a situation that must be seen at once, even...
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| Angle-Closure Glaucoma |
Introduction and Overview
Glaucoma is a term used to describe a condition usually characterized by an increase in intraocular pressure (IOP) which damages the tissues in the eye.
Basic Principles of Glaucoma
The eye is filled with fluids which have the function of keeping the structures inside it, the iris, crystalline lens, and retina, in place and nourished. The largest part of the eye, called the posterior chamber, is filled with the vitreous body, also known as the vitreous humou...
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| Aniseikonia: Perceiving Different Sized Images |
Humans are usually a little bit asymmetrical; this is why it is said that there are no two people exactly alike; there are always small differences between our right and left sides. Our eyes are usually fairly similar, but sometimes there is enough difference between them that images we see with one eye are larger than those with the other. This disparity in image size perception from one eye to the other is called aniseikonia.
Aniseikonia (an-eye-seh-cone-ee-yah) is a binocular vision ...
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| Anisocoria: Unequal Pupil Size |
Normally, the pupils of the eyes are equal in size, are both round in shape and both react quickly and equally to light and any change of focus. Anisocoria is the medical term that simply means the pupils are not equal. The pupil also contracts when the eye changes focus from far away to close up.
The pupil is not actually a structure, but is simply a little window in the center of the colored part of the eye, the iris. The iris muscles control the size of the pupil, making it larger i...
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| Arcus Senilis & Arcus Juvenilis |
Usually the cloudy band is about one millimetre wide and is visible in the mirror when you look closely. It has no impact on vision. This common age-related condition occurs within the cornea. It is present in 60 percent of patients between the ages of 40-60 years and in nearly all patients over the age of 80. It appears as an arc-shaped whitish deposit; it often looks dull or hazy like a milky-white or yellowish Saturn-like ring around the outer edge of your cornea and it is caused by a de...
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| AREDS: The Age-Related Eye Disease Study |
Everyone over the age of 55 should have an eye exam to determine their risk of developing advanced AMD. In 1992 the U.S. National Eye Institute initiated the Age-Related Eye Disease Study (AREDS) to see if high doses of antioxidants and zinc would have any effect on people with AMD. The goal was to determine if these supplements could help stop or slow down the progression of AMD and vision loss.
There were 3 640 people between the ages of 55 and 80 who participated in the study. By the time it...
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| Asteroid Hyalosis |
This is the only eye condition that can make the inside of your eye look like a star-struck night sky. The only problem is that you can’t see it for yourself, unless your eyecare practitioner takes a photograph of the inside of the eye. Normally, there are no symptoms of asteroid hyalosis at all, and in fact most people who have it don’t know it.
The eyes are filled with a substance called the vitreous humour, or vitreous body, which is a transparent gelatin that...
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| Astigmatism |
Refraction is the term used to describe the testing procedure used to determine what lens prescription a patient may need to see well. Light bends when it passes through lenses or prisms, and also when it passes through the surfaces of the eye. The first major surface that light passes through on its way to the retina is the cornea.
Astigmatism is one of the common refractive errors, along with myopia (nearsightedness) and hyperopia (farsightedness). Pronounced "ah...
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| Atrophic Retinal Holes |
The retina is the thin, light-sensitive nerve fiber layer lining the back of the eye that receives light and visual images through the rest of the eye. It is held up next to the back wall of the eye by the vitreous body, also known as the vitreous humour, a stiff, gelatinous substance. The vitreous is actually attached to the retina in several places, most notably around the periphery of the retina, just in front of the midline equator of the eye, and around the optic nerve h...
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