Scleral lenses in focus

Contact lens optician, Nick Howard, outlined how three scientists navigated language barriers and limited materials to design the first scleral contact lens during his talk at 100% Optical (ExCeL London, 24–26 February).

In Scleral lenses: back to basics, Howard shared that German ophthalmologist Adolf Fick, glassblower Friedrich Anton Mueller and French optician Edouard Kalt were among those working during the Victorian era to develop a wearable contact lens.

This period of innovation culminated with a design published by Fick in 1888.

“This was the first documented design of a workable scleral lens,” Howard shared.

“The question mark is, how did the Victorians know what curves to use?” he added.

Howard explained that the scientists used plaster of Paris on cadaver eyes, before comparing the cast to the eyes of the patient.

He shared a photo of the first Mueller-Welt glass contact lens, produced in 1889.

“This was 135 years ago and they have just about nailed it,” he observed.

However, without a slit lamp or corneal topography there were limitations in what could be achieved. Howard noted that the first contact lenses only allowed for a limited wear time.

“They were getting about two hours of wear out of the contact lens and then everything went pear shaped,” he said.

Howard explained that the scientists had not taken into account the lens settling into the eye, adding that while glass is easy to manufacture and transparent, it is also relatively heavy.

Scleral lenses were worn by some aspiring myopic RAF pilots during World War II, although this was kept secret. 

“That was the only way that they could get to fly airplanes,”

“They were scared all the time that the RAF would find out that they were wearing contact lenses,” Howard said.

Compared to when Howard graduated as a contact lens optician in 1984, the use of rigid gas permeable (RGB) lenses has declined in comparison to soft contact lenses.

At the time of his graduation, around half of contact lenses fitted were RGB compared to one in ten lenses prescribed in 2022.

Howard shared that while there have been many changes in contact lenses since he graduated four decades ago, many of the same fundamental considerations apply.

“Patients want good vision and comfort. Practitioners want ease of fitting,” he said.

He highlighted that the idea that scleral lenses are challenging to fit is a misconception, while they can provide benefits to patients.

“There are dry eye clinics popping up across the country that are fitting scleral lenses with a high level of success,” he added.

Howard shared the example of a patient with corneal dystrophy who had both reduced vision and discomfort in her existing lenses.

“The patient would complain that her vision was like looking through a bathroom window,” he said.

After fitting the patient with a scleral lens, she experienced an improvement in symptoms.

“We could see the body language of the patient change… it’s like taking an uncomfortable pair of shoes off,” Howard said.