Under SubChapter III, section 12181. paragraph (7) (F) of the Americans With Disabilities act (ADA), a "professional office of a health care provider, hospital, or other service establishment;" is a public accommodation.
Section 12182 (a) provides that:
No individual shall be discriminated against on the basis of disability in the full and equal enjoyment of the goods, services, facilities, privileges, advantages, or accommodations of any place of public accommodation by any person who owns, leases (or leases to), or operates a place of public accommodation.
Section 12182 (b) (1) (A) provides that:
(i) Denial of participation
It shall be discriminatory to subject an individual or class of individuals on the basis of a disability or disabilities of such individual or class, directly, or through contractual, licensing, or other arrangements, to a denial of the opportunity of the individual or class to participate in or benefit from the goods, services, facilities, privileges, advantages, or accommodations of an entity.
(ii) Participation in unequal benefit
It shall be discriminatory to afford an individual or class of individuals, on the basis of a disability or disabilities of such individual or class, directly, or through contractual, licensing, or other arrangements with the opportunity to participate in or benefit from a good, service, facility, privilege, advantage, or accommodation that is not equal to that afforded to other individuals.
Section 12182 (b) (1) (D) provides that:
(D) Administrative methods
An individual or entity shall not, directly or through contractual or other arrangements, utilize standards or criteria or methods of administration
(i) that have the effect of discriminating on the basis of disability
Section 12182 (b) (2) (A) provides that:
For purposes of subsection (a) of this section, discrimination includes: ...
(ii) a failure to make reasonable modifications in policies, practices, or procedures, when such modifications are necessary to afford such goods, services, facilities, privileges, advantages, or accommodations to individuals with disabilities, unless the entity can demonstrate that making such modifications would fundamentally alter the nature of such goods, services, facilities, privileges, advantages, or accommodations;
(iii) a failure to take such steps as may be necessary to ensure that no individual with a disability is excluded, denied services, segregated or otherwise treated differently than other individuals because of the absence of auxiliary aids and services, unless the entity can demonstrate that taking such steps would fundamentally alter the nature of the good, service, facility, privilege, advantage, or accommodation being offered or would result in an undue burden;
It would seem that failure of the people in the office to give assistance would constitute a violation of Section 12182 (b) (2) (A) (iii) and that giving such assitance would be required as a reasonable modification under Section 12182 (b) (2) (A) (ii). Section Section 12182 (a) and Section 12182 (b) (1) (A) would also seem to apply.
Filing an actual suit under the ADA would be a possibly costly and time consuming solution, however. It would probably require a lawyer knowledgeable in DA practice. Possibly merely pointing out to the office staff that such assistance is needed, or if that does not work that the ADA requires such assistance would suffice.
As a different possible solution, many (but not all) legally blind people are able to read printed materiel and fill out forms with the help of an assistive device, such as a light-and-magnifier system. Some years ago I helped a legally blind friend obtain such a system, and she found it very useful.