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Understanding and Coping with Achromatopsia UNDERSTANDING AND COPING WITH ACHROMATOPSIA by Frances Futterman Second Edition A Publication for The Achromatopsia Network P.O. Box 214 Berkeley, CA 94701-0214 USA WWW: http://www.achromat.org/ Understanding and Coping with Achromatopsia (2nd edition) Copyright © 1998 – 2004 by Frances Futterman All rights reserved. No part of this publication (with the exception of pages clearly intended for distribution, such as the page about the Achromatopsia Network and the pages about publications available to networkers) may be reproduced, stored in a retrieval system, or transmitted in any form without prior approval of the author. Schools may ask for approval to reproduce specific sections for in-house distribution. Requests for permission should be addressed in writing to Frances Futterman, P. O. Box 214, Berkeley, California 94701-0214 USA. The information presented in this book has been gathered from many sources including input from members of the Achromatopsia Network, library research, and consultations with specialists in ophthalmology, optometry, vision research, and other fields. On page 140, there is a list of references which have been especially helpful in preparing the material included in this book. The author, Frances Futterman, serves as editor and reporter for the Achromatopsia Network Journal (formerly known as the Achromatopsia Network Newsletter). The Achromatopsia Network is an information and support network for individuals and families who are affected by inherited, congenital achromatopsia. Many thanks to Mark Futterman, who served as production supervisor, editorial assistant, and information resources specialist for this book. Also, thanks to all members of the Achromatopsia Network who contributed thoughts, information, personal experiences, and suggestions regarding the subject of understanding and coping with achromatopsia. Information about products and services in this publication is for your consideration only and does not imply a recommendation. - ii - Contents Page What is achromatopsia? ....................................................................1 What is it like to have achromatopsia?.............................................2 Comparing achromatopsia with other vision disorders ..................4 Vision and coping strategies of a complete achromat ....................5 Inheritance factors associated with rod monochromacy ................8 The genetics of rod monochromacy ...............................................10 The genetics of blue cone monochromacy ....................................12 Achromats who see color ................................................................13 Getting diagnosed ............................................................................14 Achromatopsia in print ....................................................................19 About being colorblind ....................................................................25 Adapted lifestyles and adapted environments...............................29 Orientation and mobility ..................................................................32 Accommodations in the workplace and elsewhere .......................37 Vocational choices for persons with achromatopsia.....................38 Social and psychological aspects of achromatopsia ....................40 Using adaptive devices ....................................................................44 Options for magnification ................................................................46 Adapting indoor lighting for achromats .........................................48 Making reading easier ......................................................................49 Special needs in school ...................................................................51 Reading formats used by achromats ..............................................54 Options in tinted lenses for persons with achromatopsia ............57 Networkers’ input regarding tinted lenses .....................................76 What are the best lenses for achromats? .......................................94 Sources for tinted lenses and related products...........................114 Sports experiences of networkers ................................................115 Scientific studies of achromatopsia .............................................116 Genetic research studies of rod monochromacy.........................118 Disclosure of visual impairment ...................................................121 Accessing services for the visually impaired ..............................122 About not being blind ....................................................................124 Other vision problems which can affect achromats ....................128 Types of vision care specialists ....................................................131 Misdiagnosis, uncertain diagnosis, and related matters ............132 Ways to help people understand how achromats see .................136 References ......................................................................................140 The Achromatopsia Network .........................................................141 Other useful information ........................................................ 142-156 - iii - What Is Achromatopsia? Congenital achromatopsia is a rare less affected than distance vision. The hereditary vision disorder which affects average visual acuity of persons with 1 person in 33,000 in the U. S. The inci- achromatopsia is from 20/160 to 20/200, dence varies in other parts of the world. using standard vision charts. Many Persons who have achromatopsia achromats also have refractive vision have little or no “cone vision.” In normal problems, ranging from extreme near- eyes there are 6 million “cone” photo- sightedness to extreme farsightedness. receptors, located mostly at the center Many of them have a significant degree of the retina. Achromats must rely on of astigmatism, more than is found in their “rod” photoreceptors for vision. In the general population. Forms of stra- normal eyes there are 100 million rods, bismus (eye turns) are also common. located mostly at the periphery of the In eye exams vision care specialists retina. Rods “saturate” at higher levels look for the following symptoms and of illumination. They do not provide signs when diagnosing achromatopsia: color vision or “detail vision.” Achromats ✮ Poor visual acuity (detail vision) are, therefore, either totally – or almost ✮ Photophobia – aversion to light totally – colorblind, have poor visual ✮ Little or no color perception acuity, and are unable to adapt visually ✮ Normal or nearly normal fundus to higher levels of illumination. There (the back of the eye) are variations in the severity of these ✮ Stable condition (present from early symptoms among individual achromats. infancy and not progressive) There are complete rod monochromats, ✮ Abnormal or absent photopic ERG incomplete rod monochromats, and (electrical recording from the eye blue cone monochromats. under light conditions in which the The word achromatopsia means cones would normally function) “without color vision.” Monochromacy ✮ Normal ERG for rod vision means to see in shades of only one ✮ Nystagmus – “Shaky eyes” color. Many people assume that rod The nystagmus varies with: monochromats, lacking normal color 1. Distance: more nystagmus when vision, see in shades of gray. However, trying to focus in the distance complete rod monochromats report that 2. Light level: less nystagmus in the word “gray” has no more meaning low light, more in bright light for them than do any of the names for 3. Fixation: nystagmus is worse all the other colors they cannot see. when trying hard to see. They perceive many gradations 4. Age: usually more pronounced (shades) from white to black; and, in infancy and childhood and unless they are being required to use tends to diminish with age. correct color names to communicate with normally sighted people, they tend There is a rare medical condition, to describe something as “darker than” cerebral achromatopsia, which is an or “lighter than” something else. acquired form of total colorblindness Since cones are concentrated in the and which can occur as a result of macular (central) area of the retina, they stroke, trauma, or some other cause. are responsible for good central vision. Persons with this condition do see in A deficiency in cones results in sub- shades of gray, because they previously normal visual acuity which cannot be had color vision and so are able to corrected with Rx lenses. Near vision is perceive the absence of color as gray. - 1 - What Is It Like certain other eye conditions. Light does not “hurt” their eyes, so to speak. How- to Have Achromatopsia? ever, some achromats report that they People with achromatopsia report have experienced pain or discomfort in that being colorblind is, by far, the least connection with having to strain to see troublesome manifestation of this vision and function in adverse conditions. But disorder. Far more serious to cope with this is visual stress, not a manifestation are the poor visual acuity (especially for of achromatopsia. distance) and hypersensitivity to light, How well achromats are able to see sometimes called photophobia. can change continually (and sometimes Strictly speaking, photophobia means significantly) with every change in illu- “fear of light.” However, anyone familiar mination. Depending on the quantity of with this term knows it does not refer light, the quality of light, the direction
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