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Retinoscope and Retinoscopy

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Retinoscope Retinoscope  Definition: A retinoscope is an instrument used to objectively determine the refractive power of the eye. It works by allowing the examiner to project a beam of light into the eye and then observe the light as it is reflected back out of the eye.  The emerging light will change as it passes through the optical components of the eye, and by judging how much it changes, the examiner can determine the refractive power of the eye. Types of Retinoscope: There are basically Static retinoscopy and Dynamic retinoscopy. Static retinoscopy  is used for routine refractions with the patient viewing a distant target. Dynamic retinoscopy  is performed when the patient focuses on a near target and is helpful in determining the accommodative ability of eyes with decreased vision and in checking for residual accommodation after administering a cycloplegic drug. Retinoscopy: is a technique to obtain an objective mea...

How People With Different Kinds of Color Blindness See the World

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According to data available on the most comprehensive resource about color blindness, quite a lot of us — around 0.5% of women and 8% of men — suffer from inaccurate perceptions of color. To Be Seen Optom has compared how people with different kinds of color blindness see the world, and it turns out that most of them certainly don’t just perceive it in black and white. There are several different categories of color blindness, but we focused on the most common ones. The results are fascinating. A person with normal vision sees the world around them in these colors. Deuteranomalia is the most common form of color blindness. Around 4.63% of men suffer from it and in many cases don’t even realize. It’s clear from the photo that the colors have lost some of their brightness, especially with regard to green and red. Protanopia...

Glaucoma: Types, Symptoms, Diagnosis And Treatment

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Glaucoma refers to a group of related eye disorders that all cause damage to the optic nerve that carries information from the eye to the brain. Glaucoma usually has few or no initial symptoms. In most cases, glaucoma is associated with higher-than-normal pressure inside the eye — a condition called ocular hypertension. But it also can occur when intraocular pressure (IOP) is normal. If untreated or uncontrolled, glaucoma first causes  peripheral vision loss  and eventually can lead to blindness. Basic causes of peripheral vision loss include: Glaucoma. Retinitis pigmentosa. Eye strokes or occlusions. Detached retina. Brain damage from stroke, disease or injury. Neurological damage such as from optic neuritis. Compressed optic nerve head (papilledema) Concussions (head injuries) On the basis of the available data, we estimate that there are approximately 11.2 million persons aged 40 years and older with glaucoma in India. P...

Differential diagnoses - Conjunctivitis and iritis in pictures

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How to differentiate between these allergic and infective eye conditions. Acute iritis Presentation Painful inflammation of the iris. Uncommon in children Can be acute, chronic or relapsing May be associated with other conditions, such as rheumatoid arthritis, Behcet's disease (BD), malignancy, trauma to the eye and infection Signs and symptoms may include any or all of the following: Pain in the eye or brow region. Worsened eye pain when exposed to bright light. Reddened eye, especially adjacent to the iris. Small or funny shaped pupil. Blurred vision. Headache. Management Attacks typically only involve one eye at a time. Without correct treatment, iritis can  cause permanent visual problems. Young and middle-aged people are most commonly affected. There is no  cure , but treatment of individual episodes  can  control inflammation and prevent complications. Usually requires referral to secondary care Treatment is us...

What Is Retinoblastoma ?

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Retinoblastoma is cancer of the eye that begins in the retina, the layer of light-sensing cells lining the back of your eye that converts light rays into impulses. The impulses are sent through the optic nerve to your brain, where they are recognized as images. Retinoblastoma, which can occur in one or both eyes, usually affects young children, but can infrequently occur in adults. Retinoblastoma Causes : Retinoblastoma occurs when retinal nerve cells genetically mutate, causing them to grow and multiply, eventually forming a tumor. These cells usually spread into the eye and nearby structures, and can also spread to other areas of the body (metastasize), including the brain and spine. It is usually not known what causes the genetic mutations that lead to retinoblastoma; however, children may inherit a genetic mutation from their parents. Children with hereditary retinoblastoma tend to develop it at an earlier age, and it usually occurs in both eyes. Retinoblasto...

Too Much Use Of Mobile Phone Can Cause Eye Cancer – Experts Warns

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Experts have warned mobile phone users that regular use of cellphones could increase risk of contracting eye cancer. Mobile phones have been linked to a rare form of eye cancer. A German study suggests that regular use of cellphones could lead to an increased risk of contracting uveal melanoma, in which tumours form in the layer that makes up the iris and base of the retina. The cancer affects just a few in every 100,000 people but the study comes on top of many other conflicting claims about the dangers of mobile phones. A report commissioned by the British Government last year said that, despite the widespread fears, no conclusive links with cancer had been proven. Conversely, because there was also no proof that the phones were safe, it recommended that use by children, at least, should be limited. The German study, to be published this month in the journal Epidemiology, follows research among 118 patients with the eye cancer. Dr Andreas Stang of the Univ...

Testing Equipment

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We utilize many instruments and specialized equipment to help evaluate your eye health and treat your eye conditions.  Some of these instruments are used for routine eye exams, and others are for analysis of specific eye health conditions.  This page will give you an idea of what to expect from each instrument and some of the reasoning behind their use. Auto-Refractor Keratometer This instrument automatically measures an objective refraction, or theoretical refraction of what lens powers you should need to see good in the distance.  You just look into the instrument where you see a picture.  The instrument looks to see where light focuses on the back of your eye, and what lenses it would take to make the image focus in the right area.  It measures sphere, cylinder and axis for each eye, as well as radius of curvatures and axis for the cornea of each eye. These measurements will give us a good idea if you have a change in your prescription, or a...