Hanan Haulani El Harak Thesis - June 18

On June 18, 2026, at 11:30 a.m., the public defense of the doctoral thesis of Hanan Haulani El Harak will take place, titled Estudio de las causas y propuesta de medidas para reducir la tasa de abandono en usuarios de lentes de contacto. The event will be held at the Auditorium of the Centre Universitari de la Visió (CUV) of the Faculty of Optics and Optometry of Terrassa (Passeig del Vint-i-dos de Juliol, 660. 08222 Terrassa).

The research has been supervised by Dr. Joan Gispets Parcerisas and Dr. Aurora Torrents Gómez, and it is part of the PhD program in Optical Engineering of the Department of Optics and Optometry at UPC.

Estudio de las causas y propuesta de medidas para reducir la tasa de abandono en usuarios de lentes de contacto.

The use of contact lenses (CL) is an excellent and fully established optical option. However, professionals and patients face a constant challenge: early and unplanned drop-out. Why do many users stop using them shortly after starting?

The real reasons behind drop-out

Contrary to what one might think, the issue is usually not how well the patient sees. Research confirms that visual quality is not a determining factor in stopping contact lens wear. Instead, the red flag lies in comfort and support:

• Discomfort and dryness: Foreign body sensation and dry eyes remain the primary causes.

• Initial handling: Difficulties in inserting and removing lenses during the first few days lead to frustration.

• Lack of follow-up: Many users find themselves "on their own" once they leave the practice, without regular clinical control.

• Environmental factors: Certain environmental conditions (air conditioning, screens, etc.) act as modulators that worsen the experience.

How was the research conducted?

To reach these conclusions, the thesis was structured around three main blocks of work:

1. Literature review: Analysis of the state of the art on a global level.

2. Observational studies: Patients were analyzed in three different environments: clinical, university, and retail optometry practice, detecting in the latter some access barriers and deficiencies in the fitting process.

3. Good practice guide: A structured follow-up protocol was designed and implemented, applied directly at the CUV (Centre Universitari de la Visió).

The solution: More guidance and standardized protocols

The major contribution of this thesis is that it proves with data that drop-out can be prevented. The implementation of the structured fitting guide at CUV has shown that the drop-out rate can be drastically reduced while improving user satisfaction by acting on three pillars: Structured clinical guidance, active patient education (how to care for the lenses, how to handle them), and the standardization of protocols in the practice are the most effective tools to improve retention.

Members of the examination committee

The evaluation committee will be composed of:

• Chairperson: Dr. Maria Jesús Giráldez Fernández, Tenured Professor at Universidade de Santiago de Compostela

• Secretary: Dr. Genís Cardona Torradeflot, Tenured Professor at Universitat Politècnica de Catalunya

• Member: Dr. Juan José Durbán Fornieles, Tenured Professor at Universidad de Granada

Additional Information

For more information about this thesis and other scheduled defenses in the Optical Engineering program, you can consult the website of the Doctoral School of the UPC.