Estimated that more than 14 million people in the US age 12 years older have visual impairment with less than 20/40 vision.
Of the above 14 million, 11 million are attributable to refractive error.
Uncorrected refractive error is the most common cause of visual impairment worldwide, with approximately 53% of visual impairment resulting from uncorrected refractory error.
In 2011 about 12% of US adults aged 65-74 years and 15% of those 75 years or older reported having problems seeing, even with glasses or contact lenses.
Visual impairment is common in older adults and in 2015, 217 million people were estimated to have a visual impairment worldwide, with 38.4% of them 70 years or older.
The prevalence of blindness and visual impairment increases with age among all racial and ethnic groups, and this is a particularly true among persons older than 75 years.
Visual impairment affects more than 2.9 million US adults.
Visual impairment reduces the quality of life, increases risk of falls, depression and cognition.
Visual impairment is a leading cause of disability.
Most common causes of non-refractory visual impairment or age-related macular degeneration, cataracts, diabetic retinopathy, glaucoma, and other retinal disorders.
Visual impairment is common in diabetics with 11% of adults having visual acuity of less than 20/40 and 3.8% of cases cannot be corrected with refraction.
Defined as blindness with best vision of <20/200 in the better eye, or low vision <20/40.
Increased risk of mortality among adults with glaucoma, retinopathy, and cataract.
Severe bilateral visual impairment and, to a lesser extent, milder visual impairment are independent predictors of reduced overall survival and increased cardiovascular disease-related mortality in women.
Acute visual loss of one eye requires urgent evaluation and management.
It is critical to identify whether visual loss is due to identify whether visual loss is due to a lesion in the eye or the optic nerve.
A retinal lesion is suggested by symptoms of waviness, warped images, flashing or colored lights, or an increase in floaters in one eye.
Color desaturation is common symptom in optic nerve lesions.
Timing of visual loss is key to diagnosis of acute monocular visual loss, with optic neuritis it involves quickly and then subsequently improves, while with ischemic optic neuropathy it is sudden and static and with compressive lesions its discovery may be sudden, but its occurrence will likely be insidious and slowly progressive.
Unilateral vision loss 1.8-4 times more prevalent than bilateral vision loss.
Unilateral vision loss associated with loss of stereoscopic binocular vision and reduction in visual fields with reduced visual-motor coordination, depth perception, and spatial orientation.
Patients with unilateral vision loss are more likely to have motor vehicle crashes, a greater propensity to fall, and dependence on others, and have poorer physical and mental health than the general population.
In persons with best-corrected vision acuity reduced to 20/40 or worse in the better eye have a 70% increased risk of mortality compared with persons without visual impairment.
Prevalence of non-refractive visual impairment is increasing and may be attributable, in part, to higher prevalence of diabetes (Ko f et al).