Hyperopia (Farsightedness) occurs when your eye is too short in relation to the curvature of your cornea. With hyperopia, distant objects are seen more clearly than near objects. Hyperopia is the medical term for “farsightedness. ” Hyperopia occurs when your eye is too short in relation to the curvature of your cornea. Light rays entering your eye focus behind the retina, producing a blurred image. Some farsighted people can use their focusing muscles to pull the image forward onto the retina, allowing them to see clearly. But others, who cannot overcome the effects of severe hyperopia, need glasses for distance vision as well as reading glasses or bifocals.
Below shows the categories of severity for hyperopia:
• Mild Hyperopia < +2.00 diopters
• Moderate Hyperopia +2.00 to +4.00 diopters
• Severe Hyperopia +4.00 to +6.00 diopters
• Extreme Hyperopia > +6.00 diopters
Myopia (Nearsightedness) occurs when your eye is too long in relation to the curvature of your cornea. With myopia, near objects are seen more clearly than distant objects.
More than 70 million people in North America (about one in four) are nearsighted. Myopia is the medical term for nearsightedness. It occurs when your eye is too long in relation to the curvature of your cornea. Myopia causes light rays entering the eye to focus in front of the retina, producing a blurred image. The term “nearsighted” means that you can see objects that are “near” to you more clearly than distant objects. The more myopic you are, the more blurred distant objects appear, the higher your prescription in diopters and the thicker your glasses.
Below shows the categories of severity for myopia:
• Mild Myopia < -3.00 diopters
• Moderate Myopia -3.00 to -6.00 diopters
• Severe Myopia -6.00 to -9.00 diopters
• Extreme Myopia > -9.00 diopters
Astigmatism occurs when your cornea is shaped like an oval. With astigmatism, more than one focal point within the eye distorts what you see.
Many patients with myopia and hyperopia have some degree of astigmatism, or an oval shape, to their cornea. It occurs when your cornea is shaped more like a football than a basketball. As a result, you experience distortion or tilting of images due to the unequal bending of light rays entering your eyes. People with high degrees of astigmatism have blurred vision for both near and distant objects.
Below shows the categories of severity for astigmatism:
• Mild Astigmatism < 1.00 diopters
• Moderate Astigmatism 1.00 to 2.00 diopters
• Severe Astigmatism 2.00 to 3.00 diopters
• Extreme Astigmatism > 3.00 diopters
Age-related nearsightedness is one of the most common cosmetic problems of humankind. While the patient is deciding on whether or not to have the surgery, cosmetic nature of the problem should be explained to the patient and no harm should be caused during the surgery.
Presbyopia; The intra-ocular lens changes its shape to increase refractivity and focuses on the near. We can liken this to the zoom function of a camera.
After the age of 40, lenses lose this capability and experience difficulty focusing on near. This is result of physiological aging and eye-glass number increases by +1 number every ten years following age 40.
Difficulty seeing in the soft light, or holding the newspaper further to see it better are signs of presbyopia.
How do other eye diseases affect presbyopia?
While myopic patients can usually stop using their existing glasses after the age of 40 and see near, hypermetropic patients usually need a new set of reading glasses.
Presbyopia usually starts at forties and unfortunately can be seen in everyone. It is the most important problem still not solved by doctors of refractive surgery.
It is a treatable vision problem that is usually seen with increasing age. Cataract can be treated easily and successfully with developing surgery methods and intraocular lens technologies.
Cataract is usually seen related to aging. The intraocular lens that normally should be transparent loses its transparency, becomes opaque and changes color; as a result, the patient starts experiencing problems related to vision.
It is treatable; however, the treatment is only a surgical one.
Causes of Cataract
• Age… It is usually seen after ages 55 and 60
• Extended exposure to sun
• Tobacco usage
• Damages to the eye
• Extended steroid usage
Symptoms of Cataract
• Vision loss without pain
• Glaring or increasing sensitivity to light
• Frequently needing changes in eye-glass numbers
• Double vision in one eye
• Needing brighter light for reading
• Problems in the night vision
• Paling colors or yellowing
• My vision sometimes go blurry but then clears when I blink – This is a sign of dry eyes. If your eyes are dry the tears become very thick, and you often need to blink a few times to clear it. If this happens please start using the daytime lubricant drops more often (hourly). Contact us if it does not improve over time.
• My vision worse at the end of the day – It is normal for your eyes to get drier as the day goes on and this interferes with the quality of vision. If you work on computers or are concentrating on near work all day it can be hard to relax the eyes for distance vision and they will seem blurry. You also blink less when reading or using the computer and that makes the eyes drier. Use the lubricating drops more frequently and take frequent, short breaks from the computer to allow your eyes to move and blink more naturally.
• My eyes feel dry, gritty, watery, scratchy or feel like there is something in them – This is related to reduced tear production and dry eye, so will need to use eye lubricants. The more you use them the better this will get. Using the drops every hour is not too often. Many people want to tough it out and not use drops but this is the worst thing you can do.
What if I have itchy eyes?
This is an allergy response, so you may have got something in your eye (dust, pollen, animal hair). You can take over the-counter anti-histamine tablets (talk to your pharmacist) or use anti-histamine eye drops.