Daffanie Todd, a single mother of three school-age children, lost the last of her eyesight in 2013. She navigates her home in southwest Atlanta only by shuffling her feet across the familiar terrain. Without a guide, she cannot make her way in the outside world.

She certainly cannot accompany her children – ages 9, 8 and 5 – to and from their school, half a mile away on a street with no sidewalks and heavy traffic.

But Atlanta's school system has repeatedly denied Todd's request to provide bus service. So her children have been absent from Continental Colony Elementary since Aug. 9 – nine weeks and counting.

Attorneys with Atlanta Legal Aid filed a lawsuit on Todd's behalf last week, alleging that the Atlanta Public Schools' failure to "reasonably accommodate" Todd and her children violates the Americans with Disabilities Act. At a hearing Thursday, the lawyers will ask a federal judge to order the district to immediately provide transportation.

In a response filed late Tuesday, lawyers for APS said Todd's request would cause "incredible harm and disruption." Helping Todd, the district said, "opens the door to countless claims" from other parents.

Most ADA cases against school systems involve alleged discrimination against students. The U.S. Justice Department, for instance, recently sued Georgia, claiming that by segregating some disabled students in its "psychoeducational" schools, the state is violating the ADA.

This dispute stems from a very literal interpretation of an APS policy that reflects state law.

The district offers bus service only to students who live outside a certain perimeter – 1 1/2 miles from their school.

Anyone who lives inside the “walk zone,” the district’s transportation chief told Todd, is “ineligible” to ride the bus. And, according to the lawsuit, he added, “Ineligible means ineligible.”

District policy also requires adult supervision for young children, the lawsuit said. But, lawyers wrote to APS in September, “Ms. Todd does not have other family members or trusted friends who are available to walk her children to school in her stead.”

When the family lived in other school attendance zones in Atlanta, the lawsuit said, officials altered bus routes to accommodate Todd’s disability. This year, though, no one is willing to bend the rule.

Todd, 37, was diagnosed with a retinal detachment in 2002. Over time, inflammation and glaucoma blinded her in both eyes.

She registered her children at Continental Colony in July a few weeks after moving into the neighborhood. When she asked about bus service, the lawsuit said, she was told bus routes had not yet been set.

On Aug. 3, the first day of the school year, the children’s father, who lives on the other side of town, walked Todd and the children to school. That, according to the lawsuit, is when Todd first learned her children wouldn’t be allowed to ride the bus.

For the next three school days, the father took time off work to drop off and pick up the children at Continental Colony. But he said he could not accompany them every day. So the children – who are supposed to be in fourth grade, third grade and pre-kindergarten – haven’t been to school since.

The district proposed an alternative in mid-September, the lawsuit said: a “walking pool” in which another parent would accompany Todd’s children. Todd was not comfortable handing her children over to a stranger – a stranger she could not see. And, it turned out, the “pool” really consisted only of a couple of other students who would walk along with Todd’s.

When Todd rejected the alternative, the lawsuit says, district officials told her APS would provide no accommodations.\

In its response, APS disputed few of Todd's allegations. However, it said her children rode a bus to other APS schools only because the "walk zones" were deemed unsafe.

John Franklin, the district's executive director for transportation, said in an affidavit that he walked the route between Todd's home and Continental Colony. During his 10-minute walk, he said, he saw no "safety concerns."

If Todd's children had their own bus stop, APS said, "it would be very difficult, if not impossible, to prevent non-disabled students of non-disabled parents from also boarding the bus, which could lead to overcrowded buses."

Most of the district's response, however, disputes Todd's contention that denying bus service violates the ADA. The district says Todd's disability should give no "advantage" to her children.

The response contained several hypothetical examples of how other disabled parents might request unreasonable concessions.

For instance, "this might include a parent with anxiety disorder in the walk zone requiring the district to transport his non-disabled child so he would not be late for work," APS said.

Or, the district claimed, a blind parent who can't assist a child with homework might sue to get special help.

"The potential for abuse," APS said, "presents an untenable scenario for a district with limited resources to accommodate any number of requests by disabled parents derivatively applying their personal rights to their children."