Dietary carotenoids (lutein and zeaxanthin) and anthocyanins show retinal protective potential, yet their clinical efficacy in healthy children's developing visual systems remains unclear. We aimed to investigate whether lutein, zeaxanthin, and anthocyanin (LA) supplementation enhances visual function and vision protection in healthy school-aged children (6-10 years). Sixty-four participants were randomized to control or treatment (received LA supplementation daily) groups. Macular pigment optical density (MPOD), central foveal thickness (CFT), minimum foveal thickness (MFT), axial length (AL), spherical equivalent refraction (SER) and contrast sensitivity function (CSF) after LA supplementation were examined at baseline, 1, 3, and 6 months. ASQ-11 questionnaire was used to evaluate eye fatigue. Compared with control group, from baseline to 1, 3, and 6 months, MPOD levels were increased in treatment group, with the most significant increase at the 6-month follow-up. CFT and MFT levels were also elevated with time. Moreover, AL remarkably increased at 1, 3, and 6 months, considering it is a physiological increase caused by growth and development of children. At 6 months, the change in AL was prominently reduced in the treatment group. Besides, the reduction of SER levels was less in treatment group than that in control group. Additionally, CSF of control group and treatment group increased during the 6-month follow-up. CSF at spatial frequency 3 c/d in the treatment group was markedly higher than that in the control group at the sixth month follow-up. Furthermore, LA notably improved visual fatigue symptoms. Collectively, LA supplementation enhances visual function and vision protection in healthy school-aged children. Registration number (TRN): ChiCTR2500100376.

Pseudomyopia is a myopic shift in the refractive power of the eye due to overstimulation of the mechanism of accommodation. It is most common among children and may occur in all types of refractive errors, especially in hyperopia. The usual symptoms of pseudomyopia include asthenopia, intermittent blurry vision and sometimes diplopia. The management starts with recognition, which involves a high index of suspicion, cycloplegic refraction and relaxation of accommodation. This case series describes the management of three young adult female patients who presented with clinical features of pseudomyopia, with a focus on identifying predisposing risk factors and establishing the diagnosis.

This case report describes a rare mechanical etiology of postoperative refractive surprise - anterior displacement of an intraocular lens (IOL) secondary to localized posterior synechiae - in a patient with plateau iris syndrome (PIS) following combined clear lens extraction (CLE) and minimally invasive glaucoma surgery (MIGS). A 29-year-old man with PIS and medically refractory chronic angle-closure glaucoma underwent an uneventful left-eye CLE, goniosynechiolysis, implantation of a toric extended depth-of-focus (EDOF) IOL, and insertion of three iStent infinite® (Glaukos Corporation, Aliso Viejo, CA, USA) devices. Five weeks postoperatively, he presented with blurred vision, asthenopia, and binocular diplopia associated with a sudden -2.50 D myopic surprise. Dynamic slit-lamp examination revealed localized posterior synechiae extending from 1 to 5 o'clock. These adhesions exerted asymmetrical traction on the capsular bag, resulting in anterior displacement and temporal tilt of the IOL complex without pupillary block. The patient subsequently underwent targeted synechiolysis under local anesthesia. Postoperative biometry demonstrated an increase in anterior chamber depth (ACD) from 2.90 mm to 3.02 mm, confirming posterior repositioning of the IOL. Restoration of the effective lens position (ELP) reversed the myopic shift and resolved the patient's symptoms. This case highlights localized posterior synechiae as a rare but reversible cause of postoperative refractive surprise and underscores the importance of meticulous dynamic slit-lamp evaluation and ACD monitoring in patients with complex anterior segment conditions presenting with unexpected refractive outcomes. Timely synechiolysis may serve as a definitive and restorative intervention.

The word aniseikonia derives from the Greek words "an," "is," and "eikon," which mean "not," "equal," and "image," respectively. Aniseikonia occurs when there is a difference in an image's perceived size or shape and is often caused by anisometropia, which is a difference in refractive error. When aniseikonia is caused by anisometropia, it is called optical aniseikonia. Aniseikonia can also be caused by changes in the shape and location of the macula and is then called retinal aniseikonia.[1][2]  Aniseikonia at a young age can result in amblyopia.[3] Aniseikonia at a later age can cause asthenopia, headache, diplopia, dizziness, nervousness, imbalance, nausea, spectacle intolerance, ocular suppression, and distorted space perception.[1] It is thought that over 0.75% of aniseikonia can start to cause symptoms, that at 1 to 3% definite symptoms are present, and that more than 5% of aniseikonia is incompatible with binocular vision. In many cases, optical aniseikonia is predicted by calculating the difference in spectacle magnification of the right and left spectacle lens. In clinical practice, the rule of thumb that every 0.25 diopter of anisometropia causes about 0.25% to 0.5% of aniseikonia is often used. However, studies have shown that these rules of thumb significantly overestimate aniseikonia and direct measurements are much more accurate.[4]  Aniseikonia can be subdivided into symmetrical and asymmetrical aniseikonia. Symmetrical aniseikonia further subdivides into spherical (overall difference in magnification) and cylindrical (a difference in magnification in one orientation). Asymmetrical aniseikonia is also called distortion and occurs when perceived image size differences are unequal in different parts of the visual field. In the case of prismatic distortion, the difference in image size increases in one direction. In the case of pincushion distortion, the corners of one image are stretched more outward than the other. In the case of barrel distortion, the corners of the image appear squeezed inward. In the case of oblique distortion, one image is rotated relative to the other. Aniseikonia is most accurately measured with an eikonometer, but most clinics do not have one. Many other techniques of measuring aniseikonia exist, some of which require minimal equipment and can be done in a regular eye clinic.[5] All these tests employ different methods to dissociate the two ocular images and have developed a method to compare the shape and size difference of the images perceived by the two eyes. Aniseikonia only occurs when the eyes are being used together and does not occur if vision is suppressed or reduced, as may be the case in alternating strabismus and unilateral amblyopia or ocular disease.[3] Anisometropia also does not cause aniseikonia in specific situations described by Knapp's law. According to Knapp's law, axial anisometropia does not cause aniseikonia when the refractive difference between the eyes is solely due to a difference in the axial length (distance from the cornea to the retina) and when the correcting lens is placed at the anterior focal point of the eye which is about 16 mm in front of the cornea. However, clinical applications of Knapp's law are limited as anisometropia is usually not purely axial. The retina is usually stretched in the eye with the increased axial length (a cause of retinal aniseikonia), and placing a correcting lens at 17 mm in front of the eye is impractical.[6] Aniseikonia is treated with the surgical or medical correction of the underlying cause, optically with refractive surgery, clear lens exchange, secondary intraocular lens (IOL) placement, contact lenses, or via spectacle correction with iseikonic lenses.[1] When this is not possible, occlusion of one eye may be the only alternative.

Ametropia refers to any refractive condition that results in the image of the object in view, which does not allow for a properly focused image on the retina. As such, hyperopia, myopia, and astigmatism are all considered in these abnormal refractive disorders.[1] Hyperopia refers to a condition in which the refractive power of the eye is less than expected, causing objects in view to come to a focus at a hypothetical point behind the eye.[2] This results in a blurred image being formed on the retina. Hyperopia can be further classified into axial, curvature, index, or pathological. Myopia or short-sightedness is a condition where the image of the objects being viewed is formed in front of the retina toward the vitreous body. Myopia can also be defined as axial or curvature. Myopes are commonly known to bring print close to their faces when reading. Astigmatism refers to a situation in which the eye has different powers along the same eye. Astigmatism, therefore, results in various parts of the viewed objects being formed at different points on the retina. Astigmatism can be present with hyperopia (hyperopic astigmatism) or myopia (myopic astigmatism). An eye may also possess only astigmatism. The opposite of an ametropic state is an emmetropic state or emmetropia.[3] Ametropias can be corrected/altered inherently by normal physiological processes called emmetropization.[4][5][6] Ametropias may be congenital or acquired.[7] Epidemiology of the Ametropias Varying data exist on the prevalence and incidence of ametropias across the world. A group of researchers conducted an extensive meta-analysis of publications on refractive errors and came up with a pooled prevalence of myopia, hyperopia, and astigmatism of 11.7%, 4.6%, and 14.9%, respectively.[8] These numbers can change and differ according to the age group, gender, race, the severity of ametropia, type of daily work and activities, year of the data collection, etc.[9][10][11]  Environmental factors such as prolonged and excessive near-distanced work and habitual style of life are factors in the progression of ametropia, especially myopia.[12][13] Diagnosis The preliminary detection of most ametropias is possible using a vision test with a simple pinhole aperture. The patient is measured for visual acuity monocularly with no lens in place. The procedure is then repeated with a pinhole. An improvement in visual acuity with the pinhole over the unaided values indicates the presence of ametropia.[14] Ametropias are diagnosed by a process called refraction. This process is further split into objective and subjective refractions. Objective refraction involves a series of testing in which the examiner assesses the amount and type of ametropia without any input from the patient. Objective refraction can be carried out by retinoscopy and auto-refraction.[15][16][17] Subjective refraction involves fine-tuning an objective refraction result based on the responses given by the patient.[18][19][20] It is worth noting that ametropias may mimic more severe underlying pathologies; thus, abnormal results should be confirmed and thoroughly assessed.[21] Refraction results must include the type and severity of ametropia in the eye.

Objective: To study the prevalence and associated factors of digital eye strain among university students. Methodology: A cross-sectional survey and analytical study was conducted on 387 university students, ranging from 1st to 4th year, aged 18-23 years. The participants were digital device users who had not been medically diagnosed with any eye diseases affecting their use of digital devices. Statistical analyses were performed using the Descriptive Statistics, Chi-square test, and Fisher's exact test. Results: The prevalence of digital eye strain among university students was found to be 80.40%. The most common symptoms were headache (80.62%), burning sensation in the eyes (75.19%), and eye pain (71.06%). The study found that 30.49% were male and 69.51% were female, with an average age of 20.07 ± 0.07 years. It was found that gender (p < 0.05, Phi = 0.14), vision problems (p < 0.05, Phi = 0.20), wearing light-filtering glasses (p < 0.05, Phi = 0.12), average daily smartphone screen time (p < 0.05, Phi = 0.19), avoiding digital devices before sleep (p < 0.05, Phi = 0.22), glare (p < 0.05, Phi = 0.19), wind exposure to the eyes (p < 0.05, Phi = 0.20), and ambient air conditions (p < 0.05, Phi = 0.15) were significantly associated with digital eye strain (p < 0.05); however, the strength of these associations was small (Phi = 0.12-0.22), indicating limited practical impact. Conclusions: Digital eye strain is highly prevalent among university students. Although several factors were statistically associated with digital eye strain, the small effect sizes suggest that each factor contributes only modestly. These findings highlight the multifactorial nature of digital eye strain and the importance of considering combined behavioral, environmental, and ergonomic influences.

This article is devoted to the study of eye strain resulting from intensive use of augmented reality (AR) devices. The article provides a detailed description of a new measurement method aimed at detection of short-term effects on eye accommodation, convergence and fatigue. The method has been tested using an AR device with a Si-OLED-See-Through OTG screen present in both eyepieces and was validated with a group of 30 participants.