Low Vision Basics

Learning about vision loss means learning new terms.  Here is a quick overview of some of the most commonly used terms with links to more in-depth discussions.  You don’t have to know everything, but it will be helpful to you and your group members if you are aware of the general meanings.

Activities of Daily Living (ADL)

Tasks completed on a daily basis like dressing, bathing, eating, both inside and outside the home.

Adaptive Technology

Also called “assistive technology,” adaptive technology is any electronic device designed to enhance or take the place of vision.    These devices can include video magnifiers or closed circuit TVs (CCTVs), software programs that magnify or read aloud text on computer screen and scanners that provide audio output of scanned documents (text to speech or optical character recognition).

Second Sense has several training options for adaptive technology available for your group members.


Braille is a system of raised dots that are arranged in “cells.”  Each cell is a group of six braille dots arranged in two columns of three dots each. An entire braille cell fits under a fingertip allowing braille to be read with the touch of a finger.

Each braille cell corresponds to a single letter, a combination of letters (such as “ing”), a word, a number or a punctuation sign.

For older adults, braille is an option that can increase independence around the home and is useful for taking down phone numbers, creating labels and recording other important notes.

Functional vision loss

How vision affects the ability to complete everyday tasks like reading, personal care, moving in one’s environment.

Human Guide

People with vision loss often need some assistance to walk safely and efficiently in unfamiliar or difficult-to-navigate environments, such as dark restaurants, crowded sidewalks or airports.  Human Guide technique is a set of skills that were designed by orientation and mobility experts to help the person with vision loss and his or her guide maximize safety and efficiency when walking together.

Training in this technique is available from Orientation and Mobility instructors and Certified Vision Rehabilitation Therapist.  Second Sense can offer this training to your group.

Guide dog

The generic term for service dogs trained to guide people with vision loss.  Seeing Eye dogs are guide dogs from The Seeing Eye school.

Guide dogs go through rigorous training, from learning socialization skills as a puppy, to learning the skills they will need to guide their visually impaired partner.

Some of the skills Guide Dogs learn include:

  • Leading a person in a straight line from point A to point B
  • Stopping for changes in elevation, including curbs and stairs
  • Avoiding obstacles in their path, including overhead obstacles like tree limbs
  • Intelligent disobedience:  disobeying a command that is unsafe like stepping into oncoming traffic
  • Ignoring distractions

The person with vision loss and the guide dog are a team.  The person determines the route to the destination and the dog guides them there safely.

Low Vision Examination

A low vision exam is different from a normal eye exam given by an optometrist.  This exam, usually provided by a low vision specialist (also an optometrist), is used to determine how the visual impairment affects daily life and prescribes tools to enhance remaining vision.  Instead of using a standard eye chart, the low vision specialist will use portable charts and a device called a “trial frame” that is worn like a pair of glasses to measure visual ability.  Questions the specialist may ask relate to how a person sees in certain situations – going from light to dark, traveling at night, ability to see faces, etc.  Questions concerning one’s ability to manage everyday tasks like dressing, cooking, or reading may also be asked to determine level of function so recommendations can be made for specific tools to   manage these tasks.  The low vision specialist will also provide training on the devices prescribed to insure proper use and maximize their effectiveness.

Low Vision Specialist

A doctor of optometry or ophthalmology who specializes in the examination and treatment of low vision that is not correctable with standard eye glasses. This doctor will assess a patient’s current functional vision and prescribe devices to enhance vision.  This doctor also provides training and will refer patients for further rehabilitation training to manage everyday tasks.

Video Magnifier/CCTV

Video magnifiers, often called CCTVs or even reading machines, are a great tool of independence. These systems use a stand-mounted or handheld video camera to project a magnified image onto a video monitor, a television (TV) screen, or a computer monitor. There is considerable versatility in types of video magnifiers available today.

Second Sense has a variety of video magnifiers on display in our product center that you or your group members can try out.  Polly can also arrange a workshop on magnification and bring some of these magnifiers out to your support group.

Vision rehabilitation

The field of training that teaches a person how to adjust to vision loss and continue with the daily activities.  Vision rehabilitation is best when provided by a trained professional — a Certified Vision Rehabilitation Therapist (CVRT).  Polly Abbott is Second Sense’s CVRT.

Vision rehabilitation therapist

A vision rehabilitation therapist is specially trained to teach people with vision loss how to safely complete daily living tasks using adaptive techniques and assistive technology so a person can remain independent.  Areas of instruction include:

  • Communication skills: reading, handwriting, braille, recording skills, computer access;
  • Personal care: grooming, clothing organization, medication management
  • Home management: organizing an labeling, home repairs, financial management
  • Activities of daily living: cooking, cleaning, shopping, money organization
  • Leisure and recreation: crafts, sports,
  • Travel: orientation in different environments, moving safely indoors and outdoors, using a white cane, public transportation, human guide technique;
  • Counseling: emotional and practical support for the individual, family and friends on adjusting to vision loss.

Visual field

Visual field is the area where objects are seen when eyes are in a fixed position.

White cane

The white cane is a tool used for safe and independent travel.  A secondary function is to identify the user as a person with vision loss.

Tactile information the user receives from the cane helps to avoid obstacles in one’s path, detect drop-offs and changes in surfaces like carpet to tile.  Specialized training from a certified orientation and mobility specialist in its use provides a way for a person with vision loss to safely travel through a variety of indoor and outdoor environments.  State laws vary, but in general, cars are to yield the right-of-way or come to a total stop when a person using a white cane is crossing a street.