After teasing its new font in January, Twitter made some major changes to its website and app design this week. But while Twitter framed these updates as making the platform “more accessible,” some accessibility experts say that these changes missed the mark.

Most noticeably, tweets now appear in “Chirp,” Twitter’s proprietary typeface, and the display has even more visual contrast between the background and text. Other updates made the interface less cluttered, removing unnecessary divider lines. For people with low vision, high-contrast design can make websites more legible, but the current contrast level is so high that it’s causing strain for some users. Twitter far exceeds the minimum contrast standards set by the Web Content Accessibility Guidelines (WCAG), which provides recommendations for making websites accessible to disabled people. But web accessibility isn’t one-size fits all — while some users may need a high-contrast display, others who suffer from chronic migraines might require a more muted experience. Research has also shown that dyslexic people tend to read faster when presented with lower-contrast text.

“When the update hit, I could immediately feel pain in my eyes, and within about half an hour, I was having a tension headache,” said Alex Haagaard, a design researcher and founding member at The Disabled List. “I have a lot of chronic pain, and I cannot deliberately expose myself to something that is going to be exacerbating my levels of pain, because then that has cascade effects.”

Up until last year, Twitter’s accessibility team was volunteer-based — paid employees at Twitter would take on accessibility projects on top of their existing jobs, TechCrunch reported. In September, a few months after Twitter had released an audio tweet feature without accessibility considerations, Twitter introduced two dedicated accessibility teams within its company. But experts emphasize that including disabled people in design decisions from the get-go is necessary when implementing new features.

“They talked a good talk about how they were going to change this, that they were going to integrate accessibility and disabled perspectives more into their design processes, and from this, it seems they have not done an adequate job with that,” said Haagaard. “Engaging people from disabled communities as consultants at the high-level stages, within the research and conceptualization phase, would prevent designers from getting to a point where you’re testing something and you realize it’s fundamentally problematic and it’s too late.”

Twitter told TechCrunch that “feedback was sought from people with disabilities throughout the process, from the beginning. However, people have different preferences and needs and we will continue to track feedback and refine the experience. We realize we could get more feedback in the future and we’ll work to do that.”

On its accessibility account Twitter, acknowledged the problems that users were reporting with eye-strain and migraines after the update. This afternoon, the platform added that due to user feedback, it is making contrast changes on all buttons to make them “easier on the eyes.”

“When a design organization makes an announcement, and the accessibility organization alongside it actually has things to say about it, that means they work together, and that’s always a good thing,” said Matt May, head of Inclusive Design at Adobe. “The key thing is to continue to listen and find the people who aren’t being represented, and try to synthesize them within the rest of the system.”

It’s odd that Twitter neglected to add customization capabilities when it rolled out its higher-contrast display and new default typeface, since the company has a history of offering customization elsewhere in its user experience. Currently, users can toggle among dark, light and dim modes, make their default font size bigger or smaller, and even change the look of buttons and hyperlinks to colors like purple, orange and pink. Even before this week’s update, Twitter’s accessibility panel allowed users to enable a higher contrast mode. But still, there is no way for users to reduce the contrast or change what font the site uses, which experts cite as a design flaw. With its first proprietary typeface Chirp, Twitter sought to “improve how we convey emotion,” but users reported the font to be more difficult to read than Helvetica, which Twitter used before Chirp.

According to Shawn Lawton Henry — a researcher at the Massachusetts Institute of Technology, editor of the WCAG recommendations, and leader of the World Wide Web Consortium’s accessibility education and outreach — websites should include customization options for users to toggle among fonts, contrast levels and more. WCAG doesn’t require this currently, but Henry says that future updates of the guidelines will recommend that websites give users the option to change contrast.

“The main issue is that the default contrast should [meet the WCAG standards] and users should be able to change it. It’s not hard, right?” Henry said. “It’s fine to have a default font, but you have to make it customizable. Even if it was the most readable font known, it would still be important to allow people to change it because of individual differences.”

When asked about adding ways for users to change typefaces and contrast levels, a Twitter spokesperson said that the company had “no concrete plans to share right now, but we’re always looking at ways to improve the experience and listening to feedback.”

“I think part of the disappointment here is that they’re framing this as an accessibility thing, but it’s also really clear that it was equally about building brand identity,” Haagaard said.

While some users will override website settings with USS (User Style Sheets), Henry’s research for the World Wide Web Consortium showed that user agents like web browsers and e-book readers should provide users the ability to customize these settings more easily. Not all users are tech-savvy enough to write USS, and it’s easier for users to toggle among the accessibility settings specific to an app. This level of customization isn’t unprecedented — in June, Discord added a saturation slider in its accessibility settings, for example.

“The beauty of the web is that it’s not paper, and we can change it,” Henry said.