Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Blindness


Related Terms

  • Legal Blindness

Differential Diagnosis

  • Factitious disorder
  • Hysteria
  • Malingering

Specialists

  • Ophthalmologist

Comorbid Conditions

  • Glaucoma
  • Type 1 diabetes

Factors Influencing Duration

The age at onset, individual temperament, educational level, economic resources, and whether visual loss was sudden or gradual all affect the degree of resultant disability.

Medical Codes

ICD-9-CM:
369.00 - Blindness and Low Vision; Profound Impairment, Both Eyes; Impairment Level Not Further Specified
369.4 - Blindness, Legal As Defined in U.S.; Blindness NOS According to U.S.A. Definition

Overview

Functional blindness is the permanent loss of vision sufficient to prevent one from being self-supporting, thus requiring dependence upon another person, agency, or device in order to live. Legal blindness is defined as either the loss of central vision to the point that an individual with maximum corrective techniques can see only 20/200 or worse in the better eye, or constriction of the visual field in the better eye to less than 20 degrees of normal.

Many diseases of the eyes and the body as well as injury may cause blindness. It may be present at birth (congenital) or develop later in life (acquired). Blindness results from wasting (atrophy) of nerve and retinal cells.

Senile macular degeneration is the number one etiology of blindness in western societies. It most commonly affects individuals over 50, and among those who have lost vision in one eye, macular degeneration is the cause 22% of the time (Jackson). Of the two types of macular degeneration (exudative and atrophic), 90% of all macular degeneration vision loss is caused by the exudative ("wet") macular degeneration (Flaxel). New blood vessels grow behind the retina, and it detaches, causing loss of central vision but sparing peripheral and color vision.

Among Americans who are legally blind, the number two etiology of their vision loss is glaucoma, even though the incidence of that condition has decreased because of earlier detection, improved treatment, and greater awareness (Distelhorst).

Diabetic retinopathy is increasingly more common as a cause of blindness in the world. Both insulin- and non-insulin-dependent diabetics begin to show retinal changes 3 to 10 years after the disease begins. Macular swelling (edema), hemorrhages, and scarring (traction retinal detachment) of the inside of the eye causes blindness in this disease.

Incidence and Prevalence: Blindness affects more than 1 million individuals in the US who are over 40 years of age ("More Americans Facing Blindness").

Source: Medical Disability Advisor



Diagnosis

History: Individuals may report vision that has diminished suddenly or gradually over months or years.

Physical exam: An ophthalmoscopic exam may detect decreased pupil response to light or the presence of optic nerve swelling or wasting or changes in lens, cornea, vitreous, or retina. The blink response may be diminished. Eye movement may be abnormal.

Tests: Visual acuity and visual field tests help define the degree of vision loss. Special tests may be done if it is suspected that the individual is feigning symptoms of a disease or injury to obtain some desired outcome (malingering).

Source: Medical Disability Advisor



Treatment

Treatment depends on the underlying cause of loss of vision and blindness. Glaucoma is treated with eye drops and sometimes surgical procedures to reduce intraocular pressure. There are few treatments for macular degeneration. Some cases may be treated with laser eye procedures. Diabetic retinopathy is also treated with laser eye procedures.

Source: Medical Disability Advisor



Prognosis

Adaptation to visual loss varies. The best outcome results when referral is made for education before blindness is total. Some individuals are very independent with severe loss, and others are incapacitated by minor sight restrictions.

Source: Medical Disability Advisor



Rehabilitation

Rehabilitation programs are available to provide therapy and training to individuals suffering vision loss. Vocational programs can assist blind individuals with development of job skills. Programs may last several weeks to months. Some vocational programs may be comprehensive residential programs.

Rehabilitation teaches the individual to adapt to the loss of vision and the use of visual aids such as telescopic lenses, high convex lenses, special reader magnifiers, and image intensifiers. The individual may be referred to agencies and schools for assistance with psychological and physical adaptation to the visual loss. Therapy programs can help the blind adjust to the loss of vision and restore a sense of psychological security. The therapist will teach the individual how to rely on other senses in place of the eyes and how to remain independent by having the individual practice skills such as walking and traveling, the use of a cane, and typing. Programs are available that teach the use of Braille.

Source: Medical Disability Advisor



Complications

The eyeball is still susceptible to infection and injury and may deteriorate with time. The presence of hysteria or malingering may complicate the diagnosis.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Protecting the good eye is of paramount importance. Eye protection may need to be worn, especially if one eye has been affected by trauma. In some cases, the good eye may be patched to encourage full recovery to an injured eye (to allow an injured lens to correct to the fullest possible degree), further decreasing visual ability while the patch is in place. Visual aids may be needed at work, such as telescopic lenses, high convex lenses, special reader magnifiers, and image intensifiers. The physical environment may need to be adjusted to accommodate the needs of a visually impaired individual. A guide dog may be needed, requiring accommodations in the workplace environment. Visually impaired workers need time to learn to move about the workplace with use of a cane or a guide dog. The individual may need various devices that can include auditory cues or computer aids such as voice activated transcription computer programs. Typing skills may need to be learned. Other skills may be necessary, such as the use of Braille and the technology necessary to print in Braille.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Was loss of vision confirmed through visual acuity and visual field testing?
  • Does individual's vision loss qualify as functional or legal blindness?
  • Does individual have an underlying condition that may affect recovery?
  • Is malingering suspected?

Regarding treatment:

  • Has the underlying cause of vision loss responded to treatment? Is there anything more that can be done?
  • Has individual received assistance/training in regard to psychological and physical adaptation to the visual loss?
  • Does individual have access to appropriate visual aids?

Regarding prognosis:

  • What is the expectation for vision recovery?
  • What is the degree of vision loss? Has progression of vision loss been arrested?
  • How disabling is the vision loss?
  • Does individual have occupational options or access to retraining?
  • Can individual receive occupational re-training and visual adaptation education before blindness is total?

Source: Medical Disability Advisor



References

Cited

"More Americans Facing Blindness Than Ever Before." National Eye Institute. U.S. National Institutes of Health. 3 Sep. 2004 <http://www.nei.nih.gov/news/pressreleases/032002.asp>.

Distelhorst, James S., and Grady M. Hughes. "Open-Angle Glaucoma." American Family Physician 67 9 (2003): 1931-1944.

Flaxel, Christina J. "Use of Radiation in the Treatment of Age-Related Macular Degeneration." Ophthalmology Clinics of North America 15 4 (2002):

Jackson, Gregory R., and Cynthia Owsley. "Visual Dysfunction, Neurodegenerative Diseases, and Aging." Neurologic Clinics 21 3 (2003):

Source: Medical Disability Advisor






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