All About Eyes

All About Eyes

Optical Outlet Direct

 

Know everything you need to know and much more about your eyes with all the important information you should be aware of.

 

What is myopia?

Nearsightedness (myopia) is a common vision condition in which you can see objects near to you clearly, but objects farther away are blurry.The degree of your nearsightedness determines your focusing ability. People with severe nearsightedness can see clearly only objects just a few inches away, while those with mild nearsightedness may clearly see objects several yards away.Nearsightedness may develop gradually or rapidly, often worsening during childhood and adolescence. Nearsightedness tends to run in families. A basic eye exam can confirm nearsightedness. You can easily correct the condition with eyeglasses or contact lenses. Another treatment option for nearsightedness is surgery.

 

What is hyperopia?

Farsightedness (hyperopia) is a common vision condition in which you can see objects in the distance clearly, but objects nearby may be blurry. The degree of your farsightedness determines your focusing ability. People with severe farsightedness see clearly only objects a great distance away, while those with mild farsightedness may see clearly objects that are closer. Farsightedness usually is present at birth and tends to run in families. A basic eye exam can confirm farsightedness. You can easily correct this condition with eyeglasses or contact lenses. Another treatment option is surgery.

 

What is presbyopia?

Is the gradual loss of your eyes’ ability to focus actively on nearby objects — is a not-so-subtle reminder that you’ve reached middle age. A natural, often annoying part of aging, presbyopia usually develops after age 40. You’ll likely become aware of presbyopia when you start needing to hold print at arm’s length in order to read it. If you’re nearsighted, you might temporarily manage the problem by reading without your glasses. A basic eye exam can confirm presbyopia. You can correct the condition with nonprescription reading glasses or prescription eyeglasses or contact lenses. Surgery also may be an option.

 

What is astigmatism?

Astigmatism is a mild and easily treatable imperfection in the curvature of your eye. The condition can cause blurred vision. Astigmatism occurs when the front surface of your eye (cornea) or the lens, inside your eye, has a slightly different surface curvature in one direction from the other. Instead of being even and smooth in all directions, the surface may have some areas that are flatter or steeper. When the cornea has a distorted shape, you have corneal astigmatism. When the lens is distorted, you have lenticular astigmatism. Either type of astigmatism can cause blurred vision. Astigmatism blurs your vision at all distances. Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. The condition tends to remain constant, neither improving nor deteriorating much over time. Astigmatism is common and affects most people to some degree. Often it’s not pronounced enough to require corrective action. But when it is, treatments include corrective lenses and surgery.

 

What is glaucoma?

Glaucoma is the leading cause of vision loss. The most common form of glaucoma, primary open-angle glaucoma, develops gradually, giving no warning signs. Many people aren’t even aware they have an eye problem until their vision is extensively compromised. Glaucoma is not just one disease, but a group of them. The common feature of these diseases is damage to the optic nerve, usually accompanied by an abnormally high pressure inside your eyeball. The optic nerve is a bundle of more than a million nerve fibers at the back of your eye. It’s like an electric cable made up of thousands of individual wires carrying the images from the inside back wall of your eyeball (retina) to your brain. Blind spots develop in your visual field when the optic nerve deteriorates, usually starting with your peripheral (side) vision. If left untreated, glaucoma may lead to blindness in both eyes. Fortunately, medical advances have made it easier to diagnose and treat glaucoma. If detected and treated early, glaucoma need not cause even moderate vision loss. But having glaucoma does mean regular monitoring and treatment for the rest of your life.

 

What is macular degeneration?

Age-related macular degeneration is a chronic eye disease that occurs when tissue in the macula, the part of your retina that’s responsible for central vision, deteriorates. The retina is the layer of tissue on the inside back wall of your eyeball. Degeneration of the macula causes blurred central vision or a blind spot in the center of your visual field. The first sign of macular degeneration may be a need for more light when you do close-up work. Fine newsprint may become harder to read and street signs more difficult to recognize. Gray or blank spots may mask the center of your visual field. The condition usually develops gradually, but sometimes progresses rapidly, leading to severe vision loss in one or both eyes. Macular degeneration affects your central vision, but not your peripheral vision; thus it doesn’t cause total blindness. Still, the loss of clear central vision — critical for reading, driving, recognizing people’s faces and doing detail work — greatly affects your quality of life. The condition tends to develop as you get older, hence the “age-related” part of its name. Macular degeneration is the leading cause of severe vision loss in people age 60 and older. The damage caused by macular degeneration can’t be reversed, but early detection and treatment may help reduce the extent of vision loss.

 

What is pterygium?

Pterygium is a triangular-shaped lump of tissue which grows from the conjunctiva (the thin membrane which covers the white of the eye) on to the cornea (the clear central part of the eye). Pterygia often occur in both eyes, usually on the side of the eye closer to the nose. The exact causes of pterygia are not known, but they are strongly associated with exposure to ultraviolet radiation and hot, dry environments. Pterygia are not dangerous, although they can look ugly and cause some discomfort. The main problem with pterygia is that as they grow on the cornea they distort it, interfering with vision. If the pterygium grows on to the central part of the cornea it can begin to block light from entering the eye. Although a pterygium is not dangerous, it should be checked to make sure that it is not something more serious.

 

What are cataracts?

A cataract is a clouding of the normally clear lens of your eye. Looking through a cloudy lens is like trying to see through a frosty or fogged-up window. Clouded vision can make it more difficult to read, drive a car — especially at night — or see the expression on a friend’s face. Cataracts commonly affect distance vision and cause problems with glare. They generally don’t cause irritation or pain. Most cataracts develop slowly and don’t disturb your eyesight early on. But as the clouding progresses, the cataract eventually interferes with your vision. Early on, stronger lighting and eyeglasses can help you deal with vision problems. But if impaired vision jeopardizes your normal lifestyle, you might need surgery. Fortunately, cataract removal is generally a safe, effective procedure.

 

What happens in an eye test?

A complete eye exam involves a series of tests designed to evaluate your vision and check for eye diseases. It doesn’t hurt. Our optometrists may use instruments to aim bright lights directly at your eyes and request that you look through a seemingly endless array of lenses. Each test evaluates a different aspect of your vision. The eye exam usually begins with our optometrist asking about your medical history and any vision problems you might be experiencing. Next, we make a quick check of your eyes using a light to ensure the exterior parts of your eyes are functioning correctly. Finally, we measure your visual acuity, assess your need for glasses and examine your eyes for signs of disease.

 

What are the common tests during an eye examination?

Eye exams involve more than testing your vision — and, if you need glasses or contacts, determining how strong your correction should be. Additional tests assess the appearance and function of all parts of your eyes.

 

Eye muscle test

This test examines the muscles that control eye movement, looking for weakness or poor control. Your eye doctor looks at your eyes as you move them in six specific directions and as you visually track a moving object, such as a pen.

 

Visual acuity test

This test measures how clearly you can see from a distance. Your doctor will ask you to identify different letters of the alphabet printed on a chart positioned usually 20 feet away. The lines of type get smaller as you move down the chart. You cover one eye and read aloud, then cover the other eye and read aloud.

 

Refraction assessment

Refraction refers to how light waves are bent as they pass through your cornea and lens. A refraction assessment helps your doctor determine a corrective lens prescription that will give you the sharpest vision. If you don’t need corrective lenses, you won’t have a refraction assessment.

 

What are the other procedures in an eye test?

Visual field test (perimetry) Your visual field is the area in front of you that you can see without moving your eyes. The visual field test determines whether you have difficulty seeing in any areas of your peripheral vision.

 

Slit-lamp examination

A slit lamp is a microscope that enlarges and illuminates the front of your eye with an intense line of light. Our optometrist uses this light to examine the cornea, iris, lens and anterior chamber of your eye. When examining your cornea, we may use eye drops containing fluorescein (flooh-RES-ene) dye. The orange dye spreads across your eyes to help us detect tiny cuts, scrapes, tears, foreign objects or infections on your cornea. Your eyes’ tears will wash the dye away.

 

Retinal examination (ophthalmoscopy)

A retinal examination — sometimes called ophthalmoscopy or fundoscopy — examines the back of your eye, including your retina, optic disk and the underlying layer of blood vessels that nourish the retina (choroid). Usually before we can see these structures, your pupils must be dilated with special eye drops. The eye drops may sting briefly and might cause a medicinal taste in your mouth as the medication drains from your tear ducts into your throat. After administering eye drops, we may use one or more of these techniques to view the back of your eye:

 

Direct examination

Our optometrist shines a beam of light through your pupil and uses an ophthalmoscope to see the back of your eye. Sometimes eye drops aren’t necessary to dilate your eyes before this exam.

 

Indirect examination

For this exam you might lie down or recline in a chair. Our optometrist will hold each eye open and examine it with a bright light mounted on his or her forehead — a bit like a miner’s lamp. This exam lets us to see your eye in great detail and in three dimensions. Since this light is brighter than that in a direct examination, you are more likely to see afterimages, but they disappear quickly.

 

Glaucoma test (tonometry)

Tonometry measures your intraocular pressure — the pressure inside your eyes. It helps our optometrist detect glaucoma, a disease that causes pressure to build up inside your eyes and can cause blindness. Glaucoma can be treated if it’s caught early.

 

How should you prepare for an eye test?

To get the most out of the examination process expect questions about your vision history. Your answers to these questions us understand your risk of eye disease and vision problems. Be prepared to give specific information, including:

  • Are you having any eye problems now?
  • Have you had any eye problems in the past?
  • Do you wear glasses or contacts now? If so, are you satisfied with them?
  • What health problems have you had in recent years?
  • Are you taking any medications?
  • Do you have any allergies to medications, food or other substances?
  • Has anyone in your family had eye problems, such as cataracts or glaucoma?
  • Has anyone in your family had diabetes, high blood pressure, heart disease or any other health problems that can affect the whole body?

If you wear contact lenses, bring them to your appointment. Our optometrist will want to make sure your prescription is the best one for you.

 

How often should I get my eyes tested?

A regular eye examination should be conducted every 2 years or more frequently if advised by one of our Optical Outlet Direct optometrists. If you have diabetes our optometrist may recommend that you have the health of your eyes assessed each year. Some children should also have an yearly check up.

 

What is refractive surgery?

Refractive surgery (LASIK)is performed with a laser programmed to remove a defined amount of tissue from a part of your eye called the cornea. To begin, an ophthalmologist uses a special blade — or laser — to cut a flap on the top layer of your cornea, about the size of a contact lens. The flap allows access to the deeper layers of your eye. The laser is used again to flatten certain tissue or to make the tissue steeper, depending on your needs for corrected vision. Finally, the flap is folded back into place and will heal on its own.   NECESSITY FOR PERIODIC INSPECTION BY YOUR EXPRESS VISION CONSULTANT Spectacle frames, as well as lenses mounted in them, may deteriorate with use and sometimes become discoloured with time. In addition, the nose pads and the nylon threads for nylon cord frames may also deteriorate with use.

Always have your Optical Outlet Direct consultant inspect your spectacles at least once a year, and identify those components that require replacement, if any. Always replace the nose pads and the nylon threads from nylon cord frames at least once a year, not only to maximise comfort but also to protect the lenses against damage. Always consult your optical professional promptly, and obtain the necessary repairs. Talk to your Optical Outlet Direct consultants for more information and advice about any of these conditions.

This information is for general education only and may not be suitable for everyone. It is not intended to be optometric advice and if any of the issues raised effect you, we recommend you seek specific advice from your Optical Outlet Direct consultant.

 

Call (02) 9599 4090 to arrange an eye test with an Optical Outlet Direct optometrist.