An eye prescription lasts for up to 2 years with is the maximum of validity for eye prescriptions although if your eyesight gets worse faster than normal the eye prescription will last for less of a time period and may only last a year.
Contact lens prescriptions have a 1 year expiry date.
Your eye prescription and vision can become and get worse every year due to age related changes, lifestyle factors, medical or other eye conditions and eye strain.
Eye prescriptions and vision can sometimes get better and improve with age with proper eye care although for some people the eyesight may get worse as you age.
A strong eye prescription is -5.25 to -10.
Mild eye prescription is -0.50 to -3 and moderate eye prescription is -3.25 to -5.00.
The higher the numbers on your eye prescription means the worse your eyesight is and the stronger your prescription eyeglasses or contacts will need to be to correct your vision.
Normal eyesight is 20/20 vision.
The best vision is 20/20 vision and is considered to be perfect vision.
Although some people and mostly children have better than 20/20 vision and healthy eyes can go down to 20/15 vision with some accuracy.
The lowest eye vision is less than 20/1000 which is considered to be near total visual impairment or near total low vision.
20/500 to 20/1000 is considered profound visual impairment or profound low vision.
And no light perception is considered total visual impairment or total blindness.
Vision loss is considered a disability if your vision loss is severe enough that it prevents you from working or performing your normal daily tasks.
Slight vision loss is not always a disability but you can still get approved for disability payments if your vision loss is light or severe.
The more severe your vision loss the better chance you have at getting disability payments.
The 7 causes of blindness are cataracts, diabetic retinopathy, Glaucoma, Macular degeneration, Refractive errors, Trachoma and Corneal Opacity.
Other causes of blindness include Retinitis pigmentosa, Injuries and retinal detachment.
The 4 types of blindness are low vision, total blindness, congenital blindness and legally blind.
Leber congenital amaurosis can cause total blindness or severe sight loss from birth or early childhood.
The common signs and symptoms that let you know if you're going blind include.
Blurry vision.
Eye pain.
Floaters and flashers.
Sensitivity to light (photophobia).
Sudden loss of vision, or the sudden appearance of black spots in your vision.
When you're going blind you will begin to experience the presence of spots in your central vision, loss of peripheral vision and blurred vision that gets worse over time and does not clear up.
Vision loss has several causes which include cataracts, clouding of cataract lenses, scratched corneas, macular degeneration, glaucoma, AMD etc.
If you are experiencing signs of vision loss you should contact your eye doctor.
Some times of vision loss can be corrected although more severe cases of vision loss may be permanent.
If the vision loss is from cataracts or complications from cataract surgery then it can be reversed using a laser or YAG surgery.
Or in the case of cataracts the cataract surgery can fix the vision loss.
Blindness is usually a result of age-related conditions such as macular degeneration, glaucoma, or cataracts.
Although other rare conditions can also cause blindness in people of all ages.
More than 4 million adults in the United States above the age of 40 years have low vision or are legally blind.
To avoid going blind.
Exercise regularly.
Eat a diet rich in fruits and vegetables, especially green, leafy ones.
Drink coffee in moderation.
Consider taking a magnesium supplement.
Brush, floss, and visit the dentist regularly.
Don't smoke.
By age 60, around 1 in 9 people will be either blind or have MSVI.
By age 80, the ratio increases considerably: around 1 in 3 people will be either blind or have MSVI.
Signs that you may be going blind include.
Sudden loss of vision in one eye.
Sudden hazy or blurred vision.
Flashes of light or black spots.
Halos or rainbows around light.
Curtain-like blotting out of vision.
Loss of peripheral (side) vision.