Sign In

Login to ...

A-Z Index
Home > Community Outreach > New York Deaf Blind Collaborative > FAQ

Young boy in a rowboat, in a body of water (lake or ocean); land and buildings in the background.

How are different types of vision impairments classified?

Central Acuity Loss
Central visual acuity is measured against a scale of normal vision, 20/20. The higher the bottom number, (i.e., 20/60, 20/100, 20/160, etc.) the more impacted the vision is. Central vision allows us to see clear, sharp images up close and at a distance. It allows us to read, drive, and complete tasks that require fine visual details. A person with central acuity loss still has functional vision, but he/she will need accommodations in order to read print and ambulate through the environment and, if applicable, for sign language production.

Peripheral Field Loss
Peripheral vision is the vision that is outside our direct line of sight. It allows us to obtain visual details from the sides, above our head, and below our chin while still looking straight ahead. This vision creates a full picture of what is viewed. Peripheral vision is measured in degrees, with an approximate 180 degrees of usable visual fields.

Functional Blindness
A student or young adult may still have some residual vision but, due to the type of vision loss, it may not be very functional for communication or daily tasks. Therefore, this person is functioning in a way that is not reliant on vision to access the world.

Legal Blindness
Legal blindness can be defined in two ways: through central visual acuity or through peripheral visual fields. When measuring central visual acuity, an individual with 20/200 vision is considered legally blind. When measuring peripheral vision, an individual with an approximate 20 degrees of remaining functional fields of vision is considered legally blind. People who are legally blind may still have very functional vision that is helpful on a daily basis for communication and ambulatory purposes.

How are different types of hearing impairment classified?

Sensorineural hearing loss
Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain (retrocochlear). Sensorineural hearing loss cannot be medically or surgically corrected; it is permanent. Sensorineural hearing loss can be caused by diseases, birth injury, drugs that are toxic to the auditory system, and genetic syndromes. Sensorineural hearing loss may also occur as a result of noise exposure, viruses, head trauma, aging, and tumors.

Conductive hearing loss
Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones, or ossicles, of the middle ear. Conductive hearing loss usually involves a reduction in sound level, or the ability to hear faint sounds. This type of hearing loss can often be medically or surgically corrected.

Mixed hearing loss
Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.

Auditory neuropathy
Auditory neuropathy is a hearing disorder in which sound enters the inner ear normally, but the transmission of signals from the inner ear to the brain is impaired. People with auditory neuropathy may have normal hearing, or hearing loss ranging from mild to severe; they always have poor speech-perception abilities, meaning they have trouble understanding speech clearly. Often, speech perception is worse than would be predicted by the degree of hearing loss.

How are different types of deaf-blindness classified?

Types of deaf-blindness
To grasp the understanding of deaf-blindness, it is helpful to conceptualize combinations of hearing and vision loss into four possible categories.

Congenitally deaf, adventitiously blind: Individuals who are born with a severe to profound hearing loss and acquire a vision loss later in life. The onset of vision loss can be gradual or immediate; however, the commonality within this category is hearing loss. These individuals will, most likely, be visual learners and will utilize some form of sign language as their main mode of communication. This combination of loss is often seen within the larger deaf community, with the most common etiology being Usher syndrome.

Congenitally blind, adventitiously deaf: Individuals who are born with a significant visual impairment or are blind and acquire a hearing loss later in life. As in the first category, the onset of the hearing loss can either be gradual or sudden. The causes of this combination of losses can be due to trauma or various etiologies. Persons within this category most likely will rely mainly on spoken/oral communication and technology to access the world. These individuals are often braille readers or have pre-braille skills, use a cane, guide dog or mobility device for ambulating through the environment, and rely on technology to access printed materials, such as screen readers, ZoomText, etc.

Adventitiously deaf-blind: Individuals who are born hearing and sighted and then acquire both a hearing and vision loss later in life. This category is best exemplified by Helen Keller. She was born with hearing and vision and then, due to illness, lost both senses. Individuals within this category will have significantly varied life experiences due to the age of onset of each loss, the combined impact of the losses, and the cause of the losses.

Congenitally deaf-blind: Individuals who are born with a combination of both hearing and vision loss. These individuals are often challenged with a variety of other complications as the dual sensory loss has most likely occurred in utero during fetal development (due to unique and often undiagnosed syndromes), during delivery, or just after delivery through some sort of perinatal trauma. These individuals are often medically fragile and will present with a wide range of communication and cognitive abilities.

What is legal blindness?

Legal blindness can be defined in two ways: through central visual acuity or through peripheral visual fields. When measuring central visual acuity, an individual with 20/200 vision is considered legally blind. When measuring peripheral vision, an individual with an approximate 20 degrees of remaining functional fields of vision is considered legally blind. People who are legally blind may still have very functional vision that is helpful on a daily basis for communication and ambulatory purposes.


Does the child have any usable vision if he/she is legally blind?

Yes. Most individuals still have very usable/functional vision even if he/she is legally blind. In fact, depending on the degree of loss, the individual may still function visually. The individual may need modifications to print media or access to signed communication, but may still function as a mainly visual person.

How do I know if I qualify for services?

All persons can contact NYDBC for information regarding deaf-blindness, free of charge. To be a recipient of TA from the NYDBC, you must be a resident of New York State and a family member of a child with a combined hearing and vision loss, a professional serving an individual who is deaf-blind, a member of a higher education institution, a student in an academic program, etc.

How do I know if my child qualifies as deaf-blind?

If your child has both a hearing and vision loss that impacts his or her education and/or development, he or she may qualify as deaf-blind. Even if your child has one main sensory loss (such as profound hearing loss) and has a slight impairment with a second sense (such as wears glasses), he or she may fall within the parameters of deaf-blindness (see What is deaf-blindness?). Additionally, if your son or daughter has one sensory loss but has been diagnosed with a progressive loss that will affect another sense (such as Usher syndrome), or is at risk of losing vision or hearing, he/she may qualify as deaf-blind. If you are unsure and would like further information, please contact us at or 718-997-4856.

What is Technical Assistance?

Technical Assistance (TA) is an ongoing, long-term process that is designed to enhance the knowledge and skills of educators, administrators, related service providers, families and consumers on a full array of topics related to deaf-blindness. The type and level of intensity of TA that any recipient receives depends on a multitude of factors, such as need, level of commitment from the school/agency, number of students who are deaf-blind, etc.

How do I request services?

You can email ( or call (718-997-4856) the NYDBC staff to request services, or complete the Request for Services form on this website (see TA Forms section).

How do I register a child who is deaf-blind?

You can register a child who is deaf-blind by contacting us via email ( You will be sent a secure link that will allow you to register a child online. This site is password-protected and encrypted to ensure the anonymity of the information submitted. You can also contact us via phone (718-997-4856) and we will complete the registration process with you.

Who funds the NYDBC?

The NYDBC is funded by the U.S. Department of Education, Office of Special Education Programs (OSEP) for a period of five years that started on 10/1/08. These funds are allocated with the express purpose of improving services for children and youth between the ages of 0-21 who are deaf-blind.

How can I receive training?

Training or professional development is provided in two main ways: on-site or through distance learning. On-site training will be in the form of informational and hands-on workshops. Distance learning will be through the use of Blackboard and other methods such as videotaping and conference calls, which will provide supported and independent learning opportunities. Professionals will also be able to network with other professionals through various social networking opportunities (i.e., blogs, wikis, etc.).

What services are available to families?

Families can receive information, resources, and referrals on topics of interest for them and their child (i.e., communication strategies, educational planning, transition planning, etc.), and get parent leadership training through workshops or online modules, etc. They can also participate in parent-to-parent networking.

How can I network with other parents/families?

Contact the NYDBC staff and we will connect you with parents in your area and/or connect you with national organizations that are of interest to you. Contact Silvia Verga, Family Specialist, at 718-997-4855.

How can I network with other people who are deaf-blind?

Contact the NYDBC staff and we will connect you with other individuals who are deaf-blind. There are social groups and listservs that are organized by deaf-blind people for networking purposes. You can also contact the American Association of the Deaf-Blind (AADB) at and become a member. You will learn of current issues within the deaf-blind community and events happening in your area through this membership.

Is there any cost for services?

No, our services are free. NYDBC is funded with federal dollars; therefore, services are available free of charge to interested parties.


 Office Information

Queens College
65-30 Kissena Blvd, KP 325
Queens, New York 11367
Phone: 718-997-4856
Fax: 718-997-4883


Mailing Address:
65-30 Kissena Blvd, PH 200
Queens, NY 11367

NYDBC Website



 Related Links

Stay Social at QC YouTube Facebook Twitter Gray Bar Calendar MyQC QC Mobile CUNY first Blackboard QC Bookstore

Click each division to view a complete list of its departments

Adult Collegiate Education | English Language Institute | Professional & Continuing Studies
Summer Session | Weekend College | Winter Session

Resources for Combating Sexual Harassment/Sexual Assault (Title IX)

Queens College is CUNY
DirectionsMap/Directions  |  Emergency Preparedness  |  Working at QC  |  Student Consumer Info  |  A-Z Index  | 
Queens College, CUNY | 65-30 Kissena Blvd. | Queens, NY 11367-1597 | Phone: (718) 997-5000 Copyright © 2004-