The product planning department receives a variety of opinions on products from many users every day. In particular, the questionnaires attached to products that users return contain extremely valuable information. This feedback is compiled into valuable data for improving the quality and functionality of products. Yamada from the product planning department was curious about the contents of a response postcard to a product survey.

The product in question was "Shin Rohto Youjunsui," an eye drop that had enjoyed long-term market support since its launch in 1997. This eye drop was developed to meet the needs of the elderly who wanted to maintain healthy eyes regardless of age, and every aspect of it, from the brand name to the packaging and container, was carefully considered to be easily accepted by the elderly.
Surprisingly, however, the number of responses to these survey postcards coming in from young female users, primarily office workers, was increasing.

The original "Shin Rohto Youjunsui" eye drops, as its name suggests, were developed with the concept of "providing nourishment and moisture to the eyes." They contained nutrients such as vitamins and amino acids, and were effective against blurred vision and eye fatigue. These surveys indicate that this product feature had, over time, gained the support of young female users.

"Could the shift in this product's target audience be related to the increasing number of situations that strain the eyes on a daily basis, such as prolonged contact lens wear and increased computer use at work?"
Based on this hypothesis, Yamada conducted a more detailed survey targeting female users regarding their "anxiety about their eyes" in order to verify it.

A survey of 1,386 female users revealed that a staggering 89.8% reported experiencing eye strain during the day, and 92.9% of contact lens wearers felt that contact lenses were causing eye strain. While a somewhat high number was anticipated, the results far exceeded expectations.
The user feedback captured in these survey results led to the launch of the new "Rohto Yojunsui" development project.

Armed with the survey results compiled by the product planning department, Yamada knocked on the door of the product development department.
"So many people feel their eyes are being damaged?" Kurumada, the development manager, couldn't hide his surprise after reviewing the data.
Yamada conveyed to Kurumada his desire to "create better eye drops for people who are experiencing eye strain." Thus, the project members, led by Yamada and Kurumada, began considering directions for a renewal in order to create a product that would be loved by more people.

Improving a product that has been supported in the market for a long time, like "New Rohto Yojunsui," is not an easy task.
This was because it was necessary to add new features that users wanted without lowering the satisfaction level of existing users who had an attachment to the brand.
To explore development directions, the functional characteristics of existing products and feedback from users were examined from various angles. As a result, development began focusing on the point of "recovering from eye damage," which was particularly popular among users.

The previous product was formulated with gentle ingredients to meet the need for "eye drops that can be used before bed and have a mild, refreshing feel." This characteristic was also reflected in the packaging's tagline, "Just one drop before bed." However, the new "Rohto Youjunsui" needed to go a step further and have a function that actually repairs eye damage during sleep.
Therefore, Kurumada assembled a new staff to investigate the repair of damage at the cellular level.

Under Kurumada's direction, the research and development team repeatedly conducted experiments on the proliferation of corneal epithelial cells, simulating both daytime and nighttime conditions.
As a result, when comparing corneal epithelial cells exposed to light with those blocked from light, it was demonstrated that cells blocked from light proliferated approximately 1.5 times more rapidly. Furthermore, during sleep, the eyes are closed for extended periods, resulting in less exposure to external stimuli and stress.
The project members felt confident that nighttime might be more conducive to repairing eye damage than daytime, when we are exposed to light.

While maintaining the "safe formula that can be used even before sleep" of the conventional product, Kurumada set a new goal of "a formula that is highly effective in repairing corneal cells during sleep" and began designing that formula.
The project's goal was to add new value to the packaging's tagline, "One drop before bed," without changing it.

What Kurumada sought in the new "Rohto Nourishing Water" was a function that gently "nourishes" damaged corneal cells, gives the eyes a feeling of "moisture," and "repairs" them at the cellular level.

To nourish corneal cells, it is crucial to promote cellular respiration in the eye. Furthermore, by providing nutrients to corneal cells, blood circulation is improved, and their metabolism is enhanced. At the same time, it is also necessary to protect the corneal surface. While seeking a combination of ingredients that can achieve these functions, we also had to consider the characteristic of conventional products: "safe to use even before sleep."
Therefore, Kurumada proceeded with the design, incorporating various meticulous details, such as using only active ingredients that are naturally present in the eye and adjusting the pH value to 7.4, the same as tears.

Furthermore, to give the eyes a feeling of moisture, we also tried incorporating sodium hyaluronate as a viscosity agent. Hyaluronic acid is an ingredient that provides a moist feeling and has recently become more common in beauty serums and other cosmetics.
These many ingredients work together to support the self-repairing ability of corneal cells, and the goal is to find the best formula that allows the cornea to "repair" while you sleep. However, when many ingredients are used in the formula, the formulation can become unstable. After much trial and error, Kurumada succeeded in stabilizing the formulation and finally reached the prototype stage.

Meanwhile, Yamada was working to revamp the image of "Yōjunsui" while preserving its tradition. In order to appeal to a wider range of users by adding new features without changing the brand name, it was necessary to pay close attention to the packaging and containers as well.

Yamada received notification that sodium hyaluronate would be added as an additive to the new "Rohto Yojunsui" around the time they were still considering the design of the new container. Hyaluronic acid is often used as a moisturizer in cosmetics and is a well-known ingredient among female users.
Based on the keyword "hyaluronic acid," the new design was developed with the aim of creating "eye drops that are like a beauty serum, providing a moisturizing feeling to women of all ages."

Through this process, the new "Rohto Yojunsui" finally appeared as a prototype.

Yamada had been conducting an evaluation of the new "Rohto Yojunsui" package design among female employees within the company and was beginning to feel positive about the results. However, the most important thing was the actual user experience.
While there are individual differences in how people perceive eye irritation, very rarely, some individuals possess extremely sensitive eyes. Within Rohto Pharmaceutical, there are a few employees who, like "sommeliers," can keenly detect even the slightest differences in eye drop formulations.
We enlisted the help of employees with these unique qualities and had them report their impressions of how easy it was to insert the pen.

The new formula retained the strengths of the original product while adding new features, making it appealing to a wide range of users. Kurumada was confident in the prototype as the answer to this challenge. The employees, who were sensitive to the differences in eye drops, also gave positive feedback. However, Kurumada's hand, which was taking notes, stopped when he heard the opinion of one female employee.
"The scent might be a little different... Since you've put so much effort into the packaging, why not put some effort into the scent as well?"

Indeed, in the development process up to this point, which focused on enhancing the function of eye drops, the aspect of fragrance had not been considered.
"Women sometimes pay attention to the scent of their eye drops."
Shocked by this feedback, Kurumada decided to make further adjustments to the formula, which was almost complete. He also focused on creating a delicate fragrance that would be pleasant to use when applying eye drops, and repeated fine-tuning was done, incorporating the opinions of many female staff members.
And finally, the Rohto Youjunsui eye drop, part of the Kaigan Shinsho series, was completed—a product with a new concept unlike any eye drop before: "eye drops that focus on corneal cell repair during sleep."

"I've been using Yojunsui for a long time, but the packaging has been updated and it feels much better to use now."
"When I use it before bed, it's calming, and the refreshing scent soothes tired eyes, allowing me to sleep soundly."
Currently, the newly revamped "Rohto Yojunsui" is receiving the following feedback from users.

"This Rohto Moisturizing Water is sending a cheer to the eyes of our customers as they sleep tonight. We put a lot of effort into developing this product, but that was only possible because of the feedback we received from many customers. We want to continue to respond to all kinds of voices in the future," Kurumada said, reflecting on the project.

The product planning department receives new user feedback every day. And that feedback will likely inspire the next new project.