Long-Term Reduction of Short-Wavelength Light Affects Sustained Attention and Visuospatial Working Memory With No Evidence for a Change in Circadian Rhythmicity.

The short wavelength, i.e., blue light, is crucial for non-image forming effects such as entrainment of the circadian system in humans. Moreover, many studies showed that blue light enhances alertness and performance in cognitive tasks. However, most scientific reports in this topic are based on experiments using short exposure to blue or blue-enriched light, and only a few focused on the effects of its reduced transmittance, especially in longer periods. The latter could potentially give insight into understanding if age-related sleep problems and cognitive decline are related to less amount of blue light reaching the retina, as the eyes' lenses yellow with age. In this study, we investigated the effects of prolonged blocking of blue light on cognitive functioning, in particular-sustained attention and visuospatial working memory, as well as on sleep, and melatonin and cortisol levels. A group of young, healthy participants was randomly allocated to either blue light blocking or control group. Depending on the group, participants wore amber contact lenses, reducing the transmittance of blue light by ∼90% or regular contact lenses for a period of 4 weeks. No changes were observed for measurements related to sleep and sleep-wake rhythm. Dim light melatonin onset, evening levels of melatonin, and morning cortisol answer did not show any significant alterations during blue light (BL) blockade. The significant effects were revealed both for sustained attention and visuospatial memory, i.e., the longer blocking the blue light lasted, the greater decrease in performance observed. Additionally, the follow-up session conducted ∼1 week after taking off the blue-blocking lenses revealed that in case of sustained attention, this detrimental effect of blocking BL is fully reversible. Our findings provide evidence that prolonged reduction of BL exposure directly affects human cognitive functioning regardless of circadian rhythmicity.

[Visual disorder after visual contact with a geodetic laser]. / Visual disorder after visual contact with a geodetic laser.

Macular edema is a rare complication that can occur under the influence of light. Damage occurs as a result of focusing the light beam on the macula. A 23-year-old patient reported to the hospital due to a sudden reduction in visual acuity of the left eye after visual contact with a geodetic laser at work. After full diagnosis and treatment implementation after 3 weeks, vision improvement was achieved. The case report shows the harmful effects of laser techniques on human vision.

[Infective endocarditis in a patient with vision disorders]. / Infekcyjne zapalenie wsierdzia u chorej z zaburzeniami widzenia.

Roth spots are petechiae of the retina with a white or pale center that corresponds to a bundle of cotton wool or a multinuclear leukocyte aggregate. Often considered a sign of bacterial endocarditis, they are an unspecific symptom, usually more commonly seen in patients with hematopoietic system diseases. A 56-year-old patient reported to the hospital due to sudden visual impairment. The fundoscopy revealed Roth spots in both eyes that aroused the suspicion of infective endocarditis. After confirming the condition at the Department of Cardiology and the implementation of the treatment, there was a significant improvement in visual acuity, including the resolution of retinal changes. The presented case presents an accurate, still rare ophthalmic diagnosis of infective endocarditis.

[Pseudoexfoliation syndrom]. / Zespól pseudoeksfoliacji (PEX).

Pseudoexfoliation syndrome (PEX) is systematic microfibrylopathy associated with abnormalities of the accumulation of the extracellular matrix - buildup of protein clumps of abnormal basal membrane of trabecular epithelium, iris, ciliary body and lens capsule. The exfoliation material accumulates in anterior segment of a human eye (anterior lens capsule, ciliary zonule, ciliary body, iris, trabecular, anterior hyaloid membrane, conjunctiva) and other organs such as heart, connective tissue of lungs, vessels, skin, gallbladder, kidneys, liver, urinary bladder and meninges. People with PEX are more likely to develop cardio-vascular diseases, hearing loss and Alzheimer's disease as well.

[Assessment of visual acuity in aphakia patient after bilateral cataract removal]. / Ocena ostrosci wzroku u chorej bezsoczewkowej po obustronnym usunieciu zacmy wrodzonej.

Congenital cataracts are lens opacities that are already present at birth or are developing in the first years of life. Treatment consists of the surgical removal of the lens. Bilateral cataract deeply impairs vision, preventing the development of physiological reflex fixation and causes the development of nystagmus about 3 months of age. This nystagmus persists even after the surgical removal of cataracts without allowing often >0,1 visual acuity despite adequate aperture correction. Intraocular lens implants in children under the age of 1 are subject to discussion. Presents the patient's current visual acuity, in which an artificial intraocular lens was not implanted after a congenital cataract removal, retinal detachment, high myopia, glaucoma and persistent nystagmus. The whole treatment and adaptation mechanisms of the patient allowed to obtain surprising visual acuity for near vision without additional eyeglass correction.

[Fixed and temporary keratoprosthesis]. / Keratoprotezy stale i czasowe.

Keratoprosthesis is a chance for all patients who have bilateral visual loss due to corneal pathology so serious and extensive that it cannot be removed by graft transplantation. This problem mainly affects less developed countries. The eyesight of these patients could return to normal if corneal transplants were practiced and keratoprosthesis were widely available. Keratoplasty makes great progress and gets better and better results. The future will show whether there will be more reliable and biologically integrated keratoprosthesis, with low risk of complications.

[Ocular symptoms in von Recklinghausen disease]. / Objawy oczne w chorobie Recklinghausena.

Von Recklinghausen disease is a genetic disease with autosomal dominant, belonging to the group phakomatoses. In the clinical picture of the disease are skin lesions, eye, bone, intracranial tumors and other cancers of the extracranial location. Due to the high variability of clinical symptoms often diagnosis is delayed in cases of mild expression. The prognosis depends on the location and extent of the change and only symptomatic treatment have a tendency to change regrowth.