Most people are concerned when they develop vision problems, particularly if this affects their ability to see clearly.
Visual loss may be partial or complete.
- Partial - The vision is impaired or hazy.
- Complete - All or part of the vision in one or both eyes is too poor for useful function.
Also known as myopia or near sightedness
A short-sighted person can see nearby objects clearly but distant objects appear blur.
Causes of Myopia
• combination of genetic and environmental factors
• doing work that involves focusing on close objects
• greater time spent indoors
• family history of the condition
Short sightedness is a result of refractive error caused by an imperfection in the eye
This might happen because:
• the eyeball is too long or
• the eyes lens is too thick
• the cornea has too much curvature
So the light entering the eye is not focused correctly on the retina
Image falls in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision.
Symptoms of Myopia
• distant objects appear blurry
• difficult to recognize faces at a distance
• fatigue when driving or looking more than a few feet away.
• In children case, they will not being able to see the board at school clearly.
Treatments for Myopia
• Myopia can be corrected with glasses and contacts
Type of corrective lens: Concave lens
• Laser eye surgery : for permanent vision correction
- Also known as Hyperopia, or the common name long-sightedness.
- Results in clear vision of distant objects but blurred vision when looking at close objects.
- The eyeball too short, making the light rays focused at point behind the retina.
- The eye lens is too thin.
- Another cause is common in the elderly, where the lens becomes more elastic overtime. Normally the lens is thick and able to give a sharp image, in this case, the lens has ‘worn out’ and isn’t thick as it used to be.
- Some difficulties might occur when doing close up tasks such as sowing, drawing, etc.
- Neck, shoulder and back pains. For example, when the person tries to read, they might tense up muscles to accommodate for the error caused by the eye.
- Headaches are also common when one focuses too hard when reading, this will then lead to fatigue in their eyes.
- It can be treated using a convex (converging) lens to partially focus the light before it enters the eye. Hence, the creation of glasses.
- Besides glasses, one can wear contact lenses to correct the focal point. However, some people that suffer from hyperopia find contact lenses to be a bit discomforting.
-By using laser surgery, the cornea is lifted a ‘raindrop’ implant is inserted and the cornea is smoothed back down.
Astigmatism is a common vision condition that causes blurred vision.
- The cornea is irregularly shaped or sometimes because of the curvature of the lens inside the eye. An irregularly shaped cornea or lens prevents light from focusing properly on the retina, the light-sensitive surface at the back of the eye.
- Eye injury or eye surgery
- Keratoconus- cornea become thinner and cone-shaped.
- Surface of cornea shaped more like football instead basketball.
•headache after reading
•dissorted or blurred vision at ALL distance
•difficulty driving at night
•contact lenses-work by becoming first refractive surface for light rays
•refractive surgery -change shape of cornea permanently.