PURPOSE. To evaluate spontaneous eye blink rate (SEBR) and percentage of incomplete blinks in different hard-copy and visual display terminal (VDT) reading conditions, compared with baseline conditions. METHODS.A sample of 50 participants (29 females, age range, 18-74 years) were recruited for this study. All participants had good ocular health and reported no symptoms of dry eye (OSDI score < 15). Face video recordings were captured while participants observed in silence a landscape picture at 2 m (baseline) and during six different, 6-minute controlled reading experimental conditions. Texts were presented in electronic (tablet and computer display at 100% and 330% zoom levels) and hard-copy (text in book position in silence and aloud and text pasted on the computer display) formats. Video analysis was subsequently conducted to assess blink parameters.RESULTS. All reading conditions resulted in a decrease in SEBR when compared with baseline conditions (all P < 0.001), with the least negative impact corresponding to reading in a 330% expanded display. The percentage of incomplete blinks was found to increase when reading was conducted on an electronic platform, in contrast to hard-copy text.CONCLUSIONS. The high cognitive demands associated with a reading task led to a reduction in SEBR, irrespective of type of reading platform. However, only electronic reading resulted in an increase in the percentage of incomplete blinks, which may account for the symptoms experienced by VDT users.Keywords: blinking amplitude, saccades, spontaneous eye blink rate, reading task OBJETIVOS. Evaluar la frecuencia espontánea de parpadeo (FEP) y el porcentaje de parpadeos incompletos en diferentes condiciones de lectura, incluyendo texto en papel y en terminales de visualización de datos (TVD), en comparación con condiciones baseline.MÉTODOS. Una muestra de 50 participantes (29 mujeres, edades entre 18 y 74 años) fue reclutada. Todos los participantes tenían buena salud ocular y no presentaban síntomas de ojo seco (OSDI < 15). Se capturaron vídeos mientras los participantes observaban en silencio una imagen situada a 2 metros (baseline), y en seis diferentes condiciones controladas de lectura (durante 6 minutos). Los textos se presentaron en formato electrónico (tableta, pantalla con un nivel de zoom de 100% y de 330%) y papel (libro en silencio y en voz alta y texto pegado encima de la pantalla). Posteriormente, se analizaron los vídeos para evaluar los parámetros del parpadeo.RESULTADOS. Todas las condiciones de lectura provocaron una disminución de la FEP al compararlas con el baseline (todas las P < 0.001), siendo el impacto menos negativo en el caso de la pantalla expandida a 330%. El porcentaje de parpadeos incompletos aumentó durante la lectura electrónica, en comparación con papel.CONCLUSIONES. La demanda cognitiva asociada a la lectura origina una disminución en FEP en todas las plataformas de lectura. Sin embargo, sólo la lectura electrónica ocasiona un aumento del porcentaje de parpadeo incompleto, lo que puede explicar l...

Electronic sports (e-sports) have recently emerged to become a rapidly growing form of videogame competition, requiring gamers to spend many hours in front of a visual display. The nature of this new modality raises important considerations for ocular health, and visual and perceptual functioning, compared to traditional sports. In general, sports performance has been associated with open spaces, gross motor movement, and balance, while electronic sports require visual and attentional stamina at near distances with fine motor control. From an optometric viewpoint, visual perception is specific to both the sports modality and the environment where sports take place. In this topical review, we consider e-sport optometric factors such as screen time and digital eyestrain, visual skill demands, and perceptual cognitive skills such as visual attention. We compare training considerations for traditional sports and training in gaming platforms, with recommendations for future research in this growing modality. The goal of this review is to raise awareness of the various elements to consider when providing vision care to e-sport participants.

27 28Purpose: to develop and test the sensitivity of an ultrasound-based sensor to assess the 29 viewing distance of visual display terminals operators in real time conditions. 30Methods: A modified ultrasound sensor was attached to a computer display to assess viewing 31 distance in real time. Sensor functionality was tested on a sample of 20 healthy participants 32 while they conducted four 10-minute randomly presented typical computer tasks (a match-33 three puzzle game, a video documentary, a task requiring participants to complete a series of 34 sentences and a predefined internet search). Conclusions: Real-time assessment of the viewing distance of computer users with a non-42

Strabismus is not a condition in itself but the consequence of an underlying problem. Eye misalignment can be caused by disease, injury, and/or abnormalities in any of the structures and processes involved in visual perception and oculomotor control, from the extraocular muscles and their innervations to the oculomotor and visual processing areas in the brain. A small percentage of all strabismus cases are the consequence of well-described genetic syndromes, acquired insult, or disease affecting the extraocular muscles (EOMs) or their innervations. We will refer to them as strabismus of peripheral origin since their etiology lies in the peripheral nervous system. However, in most strabismus cases, that is comitant, non-restrictive, non-paralytic strabismus, the EOMs and their innervations function properly. These cases are not related to specific syndromes and their precise causes remain poorly understood. They are generally believed to be caused by deficits in the central neural pathways involved in visual perception and oculomotor control. Therefore, we will refer to them as central strabismus. The goal of this narrative review is to discuss the possible causes behind this particular type of eye misalignment and to raise awareness among eyecare professionals about the important role the central nervous system plays in strabismus etiology, and the subsequent implications regarding its treatment. A non-systematic search was conducted using PubMed, Medline, Cochrane, and Google Scholar databases with the keywords “origins,” “causes,” and “etiology” combined with “strabismus.” A snowball approach was also used to find relevant references. In the following article, we will first describe EOM integrity in central strabismus; next, we will address numerous reasons that support the idea of central nervous system (CNS) involvement in the origin of the deviation, followed by listing several possible central causes of the ocular misalignment. Finally, we will discuss the implications CNS etiology has on strabismus treatment.

The health of the ocular surface requires blinks of the eye to be frequent in order to provide moisture and to renew the tear film. However, blinking frequency has been shown to decrease in certain conditions, such as when subjects are conducting tasks with high cognitive and visual demands. These conditions are becoming more common as people work or spend their leisure time in front of video display terminals (VDT). Supervision of blinking frequency in such environments is possible thanks to the availability of computer-integrated cameras. Therefore, the aim of the present study is to develop an algorithm for the detection of eye blinks and to test it, in a number of videos captured, while subjects are conducting a variety of tasks in front of the computer. The sensitivity of the algorithm for blink detection was found to be of 87.54% (range 30-100%), with a mean false positive rate of 0.19% (range 0-1.7%), depending on the illumination conditions during which the image was captured and other computer-user spacial configurations. The current automatic process is based on a partly modified preexisting eye detection and image processing algorithms and consists of 4 stages that are aimed at eye detection, eye tracking, iris detection and segmentation and iris height/width ratio assessment.