Calculation of solar ultraviolet influx in the eye considering the field of view and pupillary dilation due to sunglasses.

The media and even the specialized literature report that the ultraviolet (UV) protection for sunglasses is critical, on the grounds that sunglasses can have a counter effect if the lenses do not provide adequate UV protection. They reason that the primary and natural mechanism is that the pupil of the eye contracts to attenuate radiation and protect the inner eye under sun exposure. Therefore, if dark lenses do not provide appropriate UV protection, there is an increased UV incidence in the inner eye due to pupil dilation, which enhances the adverse effects and impacts the ocular tissues more severely than in situations without UV protection.

Are sunglasses appropriate for driving? Investigation and prototype for public testing.

Background: Good vision through sunglasses is important to safety when driving and ISO 12312-1:2013 sets requirements for luminous transmittance and the transmittance of traffic signals.

Methods: We measured the spectral transmittances, 380-780 nm in 5-nm steps, of 232 sunglasses lenses and calculated the luminous transmittance, category (1-4) and transmittance of red, yellow, green and blue traffic signals (Q values). Furthermore, we developed a prototype for the general public to self-check sunglasses regarding safety for driving.

Building a resistance to ignition testing device for sunglasses and analysing data: a continuing study for sunglasses standards.

Background: Sunglasses popularity skyrocketed since its advent. The ongoing trend led to the creation of standards to protect consumers from injuries and secondary hazards due to spectacles use. In Brazil, the corresponding standard is NBR ISO 12312-1:2015 and since there is no mandatory testing, evaluating sunglasses performance provides an insight into compliance with the standard.

Equivalence between solar irradiance and solar simulators in aging tests of sunglasses.

Background: This work is part of a broader research that focuses on ocular health. Three outlines are the basis of the pyramid that comprehend the research as a whole: authors' previous work, which has provided the public to self-check their own sunglasses regarding the ultraviolet protection compatible to their category; Brazilian national survey in order to improve nationalization of sunglasses standards; and studies conducted on revisiting requirements of worldwide sunglasses standards, in which this work is inserted. It is still controversial on the literature the ultraviolet (UV) radiation effects on the ocular media, but the World Health Organization has established safe limits on the exposure of eyes to UV radiation based on the studies reported in literature.

Contribution to the radiation protection for sunglasses standards.

Literature establishes safe limits on the exposure of the eyes to ultraviolet radiation, for the range of 180-400 nm, including spectrally weighted and the total ultraviolet radiant exposure. Most standards for sunglasses protection only require ultraviolet protection in the spectral range of 280-380 nm to ensure the limits for effective spectrally weighted radiant exposure. Calculations of these limits were performed for 27 Brazilian state capitals, and they led to a change in the upper UVA limit to 400 nm on the 2013 review of the Brazilian standard.

Self-service kiosk for testing sunglasses.

Background: Sunglasses users may only be assured on their ultraviolet protection by purchasing certified products, however they are not able to check if sunglasses are still ultraviolet (UV) protected as they age, unless they resort themselves to a professional who is qualified for using a spectrophotometer and is acknowledged on the standards for providing a report for the user. Current literature establishes safe limits on the exposure of the eyes relatively to the ultraviolet radiation exposure for the UVA and UVB ranges (280 nm - 400 nm). The UV protection is category dependent.

Ultraviolet analysis of donated corneas: a portable prototype.

As technology improves human vision, some procedures currently performed may be causing a decrease of the natural UV protection of the cornea. A portable dual beam system prototype was assembled for physicians for clinical studies of these effects on the corneas endowing two types of 300-400 nm evaluations: 1, regularly donated corneas and 2, simulating refractive keratectomy by corneal lamellae removal. The system performs 500 measurements/s, providing ±0.

Keratometry device for surgical support.

Background: High astigmatisms are usually induced during corneal suturing subsequent to tissue transplantation or any other surgery which involves corneal suturing. One of the reasons is that the procedure is intimately dependent on the surgeon's skill for suturing identical stitches. In order to evaluate the influence of the irregularity on suturing for the residual astigmatism, a prototype for ophthalmic surgical support has been developed.

Optical projection mires for measurements of the radii of curvature of the cornea in biomicroscopes.

Keratometry is currently achieved by projecting a circular mire onto the patient's cornea and analyzing the size and shape of its reflected image. The projection mires are decisive for the precision of the measurement. We have previously developed a keratometric module for slit lamps, and the development of four projection mires are presented.

Portable light transmission measuring system for preserved corneas.

Background: The authors have developed a small portable device for the objective measurement of the transparency of corneas stored in preservative medium, for use by eye banks in evaluation prior to transplantation.

Methods: The optical system consists of a white light, lenses, and pinholes that collimate the white light beams and illuminate the cornea in its preservative medium, and an optical filter (400-700 nm) that selects the range of the wavelength of interest. A sensor detects the light that passes through the cornea, and the average corneal transparency is displayed.