Glassblower's cataracts are a form of

cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble ...

due to an occupational exposure. They are formed by many years or decades of exposure to

infrared radiation Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

while working in the occupation of

glass blowing Glassblowing is a glassforming technique that involves inflating molten glass into a bubble (or parison) with the aid of a blowpipe (or blow tube). A person who blows glass is called a ''glassblower'', ''glassmith'', or ''gaffer''. A '' lampworke ...

, or working close to hot or molten metals such with metal foundry workers or

blacksmiths A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such as gates, gr ...

. Glassblower's cataracts are due to chronic exposure to infrared radiation emitted due to the extreme heating of glass or molten metal. The infrared radiation is absorbed by the

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

and

lens A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements ...

of the eye. This causes cataracts after decades of exposure. This condition may be prevented by wearing protective glasses while practicing these occupations.

Mechanism

Glassblowers tend to work with very high-temperature objects and equipment, which emit a great deal of

through black-body radiation. The ocular lens, like all matter, has the capacity to store incident photon energy by

resonance Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied Periodic function, periodic force (or a Fourier analysis, Fourier component of it) is equal or close to a natural frequency of the system ...

absorption. Absorption of infrared photons increases vibration of molecules, which is observed as increased temperature. Large important biomolecules such as

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s tend to lose their space structure when vibrating, known as denaturation. The rate of protein denaturation is temperature dependent as described by the

Arrhenius equation In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates. The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1 ...

. Damage to biological tissue owing to the high rate of vibration damage is called thermal damage. Prior to recent research, it was theorized that one possible mechanism was the large intake of fluid due to excessive sweating on the job. Within this theory, it was suggested that the evaporation of the sweat within the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

"could lead to increased concentration of the

aqueous humour The aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the poster ...

," this increase could therefore induce the cataract. This however has not been proven to be true and instead it is generally accepted that the infrared photons as mentioned above are the primary cause of glassblower's cataracts.

Prevention

Unfortunately, there is not one clear cut way to prevent cataracts. As this specific type of cataract is associated with occupational exposures to infrared radiation, wearing protective eye equipment while on the job or taking frequent breaks can lessen the strain on the eyes. Some modifiable common risk factors unrelated to occupation are smoking, excessive alcohol consumption, deficiency in vitamin E, B1, and B2, and increased exposure of sunlight to the eyes. Risk factors that are not modifiable include previous eye injury, family history, diabetes, the use of corticosteroids, and previous eye surgery. To lessen the risk of developing cataracts it is best to limit alcohol consumption, not use or stop the use of tobacco, get adequate amounts of vitamins E, B1, and B2, and wear sunglasses and/or a wide brim hat while outside. Even if you are taking all of these steps it is still recommended that patients have eye exams every other year, or every year if over 60.

Symptoms

As with cataracts not associated with glassblowing, symptoms typically have a gradual onset. Initially, people generally are unaware they have cataracts. Blurry vision is one of the first symptoms to appear which gradually worsens as the cataracts develop further. Colors may eventually become more and more faded, eyes will become more sensitive to light, and sometimes people will have trouble seeing at nighttime. Double vision can occur and the need to change prescriptions often are also common symptoms. Over time, vision loss can occur in people who have well developed, untreated cataracts.

Diagnosis

Like symptoms, glassblowers cataracts can also be diagnosed the same way as cataracts not associated with glassblowing. To diagnose cataracts, a comprehensive

eye exam An eye examination is a series of tests performed to assess vision and ability to focus on and discern objects. It also includes other tests and examinations pertaining to the eyes. Eye examinations are primarily performed by an optometrist, ...

must be done. This exam will include dilation to measure the response of the pupils. A slit lamp examination will also be conducted to examine the cornea, iris, and other areas closer to the front of the eye. A slit lamp is used because it makes it easier for

ophthalmologists Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...

to spot abnormalities. When the eye is dilated, the pupils widen so that the ophthalmologist can see the back of the eye more clearly. The ophthalmologist will look for signs of cataracts,

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...

, and will examine the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

and

optic nerve In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial nerve that transmits visual information from the retina to the brain. In humans, the optic nerve is derived fro ...

. During this comprehensive eye exam, a

refraction In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenome ...

and visual acuity test will also be performed. These tests assess the clarity and sharpness of a person's vision and each eye is tested individually. After combining all the data collected in this eye exam, an ophthalmologist can accurately diagnose cataracts if certain conditions are met. Hinterkammerlinse 01 (fcm)

Treatment

The treatment for this condition depends on how developed the cataracts are. Early on getting a new prescription and wearing sunglasses may be all a doctor suggests. If the cataracts begin to interfere with every day life, an ophthalmologist will most likely will suggest surgery. During this surgery the clouded lens will be removed and replaced with a new, artificial lens. This lens is called an intraocular lens or IOL. The surgery itself is very safe and 9 out of 10 people who undergo this surgery can see clearer post-op.

References

{{Occupational safety and health Eye Disorders of lens Occupational diseases