Blink rate

Phenergan contains the antihistamine promethazine. Valium contains the benzodiazepine diazepam. Both the antihistamine and the benzodiazepine tend to reduce the blink rate, leading to dry eyes. Cilest is a combined oral contraceptive, which, like other oral contraceptives, may cause reduced tolerance because of corneal and eyelid oedema. 

Maurice, D. 1995. The effect of the low blink rate in rabbits on topical drug penetration. J Ocul Pharmacol Ther 11 297. 

Taylor JR, Elsworth JD, Lawrence MS, Sladek JR, Roth RH, Redmond DE (1999) Spontaneous blink rates correlate with dopamine levels in the caudate nucleus of MPTP-treated monkeys. Exp Neurol 755 214-220. 

Observe patient outside of slit lamp (blink rate, tearing, lid abnormalities, level of discomfort displayed, etc.) Noninvasive TBUT (keratometer)... 

In one study, metirosine 5.25 g caused reduced happiness, euphoria, energy, talkativeness, vigor, and attentiveness, and increased sleepiness, fatigue, sedation, and eye blink rate (4). 

Weber-Tschopp et al. (1977) exposed a group of 33 healthy subjects for 35 minutes to concentrations of formaldehyde that increased during the period from 0.03 to 3.2 ppm another group of 48 healthy subjects was exposed to 0.03, 1.2, 2.1, 2.8, and 4.0 ppm for 1.5 minute intervals. Eye and nose irritation were reported on a 1-4 scale (l=none to 4=strong) in both experiments, and eye blinking rate was measured in... 

Hypomimia—Decreased facial expression often associated with decreased blink rate. 

Any factor which decreases readability of a given message increases the amount of work needed to see and comprehend a label. Increased readability is most easily measured by increase in eye blink rate. 

Ocular Effects. Humans exposed to 600 mg/m or up to 1,800 mg/m of completely vaporized Stoddard solvent for 30 minutes in separate experiments in a controlled laborato setting showed no eye irritation as indicated by eye blinks but individuals exposed to 2,400 mg/m exhibited eye irritation as measured by eye blink rate (Hastings et al. 1984). However, subjectively reported slight eye irritation occurred in individuals exposed to 2,700 mg/m of completely vaporized Stoddard solvent for 15 minutes (Carpenter et al. 1975a, 1975b). 

Stem, J., Boyer, D. J., Schroeder, D. (1994). Blink rate A possible measure of fatigue. Human Factors, 36,285-297. 

Eyestrain, Blink Rate and Dry Eye Syndromes of Video Display Terminal Users... 

Abstract— We investigated whether the eyestrain, often experienced by subjects using a video display terminal (VDT) for an extended period of time, is due to the decrease of blink rate or to the temporarily dry eyes. Thirty-seven subjects with no dry eyes but experienced eyestrain participated in a series of experiments. The 1st experiment was performed without using VDT to obtain the control data and subsequent experiments were performed with a VDT. In those experiments we established the base line for the eyestrain, increased the blink rate and supplied the eyes with eyedrops. Blink rate, visual acuity, temporal modulation transfer function and degree of severity of eyestrain were recorded before and after each experiment. The obtained results suggested that, using the VDT causes the decrease of the blink rate that in turn produces dry eyes which causes the eyestrain. 

Keyword— Blink rate. Eyestrain, Dry eye. Temporal modulation transfer function. Video display terminal. 

From these investigations we hypothesize that people blink less when they use a VDT than when they do not use it. The decrease of blink rate will cause dry eye, which, in turn, leads to eyestrain. To test this hypothesis we performed four ejqreriments. The first experiment was performed with subjects who were not using a VDT to obtain the control data. The 3 subsequent experiments were conducted with the same subjects who were using VDT. Thus, the 2 experiment established the base line for the subject s eyestrain along with others parameters. In the 3 experiment puffs of air were used to increase the blink rate. In the 4 experiment saline droplets were used, instead, to increase the blink rate and, at... 

Eaeh subject participated in a series of 4 experiments the experiment was performed without using VDT to establish the eontrol data the 2 was performed with a VDT to establish the base line for the eyestrain the 3 was performed with a VDT and a deviee that stimulated blink rate and the 4 was performed with a VDT and a device that ejected saline droplets to the subjeef s eyes. 

Blink rate, visual acuity, TMTF curves and eyestrain were reeorded before and after each experiment. The differenees were computed and statistical analyses were used (level of significance was 0.05). All data are indicated by their average and standard deviation values. 

The blink rate (expressed as blinks per minute, bpm) was determined with the Blink Rate Recorder, described in detail elsewhere". 

To trigger the subject s blinking or to administer the droplets of sahne to the subject s eyes we used an Automatic Eyedrop Dispenser, which has been described in detail elsewhere[14]. In the study presented here, the device either contained only compressed air to stimulate the blinking rate or a 0.9% saline solution to supply additional fluid to the eyes. 

The results from the 1st experiment showed that the blinking rate fluctuated randotrdy and was 21.6 9.6 bpm The TMTF curves, visual acuity and eyestrain established before and after the experiment were not different (p>0.05). 

The results from the 3 experiment showed that the ejection of puffs of air increased the blink rate and reduced the eyestrain. The blink rate increased to 18.3 8.2 bmp. The differences of the visual acuity before and after performing the tasks was 0.17 + 0.01 i.e., a statistically significant deterioration of visual acuity. The average NES level was 0.42 0.05, which was statistically significant. By contrast, we found no difference for any subjects in the TMTF curves before and after performing the task. 

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