Vision

Both voluntary mental imagery and dream imagery involve multisensory representations without externally present stimuli that can be categorized as offline perceptions. Due to common mechanisms, correlations between multisensory dream imagery profiles and multisensory voluntary mental imagery profiles were hypothesized. In a sample of 226 participants, correlations within the respective state of consciousness were significantly bigger than across, favouring two distinct networks. However, the association between the vividness of voluntary mental imagery and vividness of dream imagery was moderated by the frequency of dream recall and lucid dreaming, suggesting that both networks become increasingly similar when higher metacognition is involved. Additionally, the vividness of emotional and visual imagery was significantly higher for dream imagery than for voluntary mental imagery, reflecting the immersive nature of dreams and the continuity of visual dominance while being awake and asleep. In contrast, the vividness of auditory, olfactory, gustatory, and tactile imagery was higher for voluntary mental imagery, probably due to higher cognitive control while being awake. Most results were replicated four weeks later, weakening the notion of state influences. Overall, our results indicate similarities between dream imagery and voluntary mental imagery that justify a common classification as offline perception, but also highlight important differences. Full article

Dry eye disease (DED) is often comorbid with psychiatric conditions and psychological disturbances like anxiety and depression. The psychological symptoms are mostly considered to be a consequence of DED or a side-effect of medication. However, the possible psychological etiology of DED is seldom explored. This study explores the relationship between anxiety sensitivity (AS), unpleasant emotional states, and the severity of DED symptoms in a healthy general population sample in Croatia. A total of 766 adults (62.27% females) aged between 18 and 88 years completed an online survey consisting of the Ocular Surface Disease Index (OSDI), Anxiety Sensitivity Index (ASI), and Depression Anxiety Stress Scales (DASS21) together with socio-demographic data. The results revealed significant positive correlations between ASI, emotional states, and OSDI (r = 0.25–0.29, p < 0.01). Mediation analysis showed that DASS21 significantly mediates the relationship between ASI and OSDI (B = 0.1, CI = [0.004, 0.2]). Highly anxiety sensitive people are more sensitive to DED symptoms, which additionally increases in a state of emotional stress. Thus, DED symptoms are perceived more intensely and frequently than in less sensitive people. Understanding these associations is crucial for comprehensive DED management, indicating potential benefits from addressing psychological health in DED patients and eye health in psychiatric patients. Full article

Retina, a light-sensitive layer of tissue of the eye, requires high levels of oxygen for its physiology. Retinal ischemia occurs due to inadequate supply of blood to the retina and choroid. Retinal ischemia is implicated in the development or progression of many ocular diseases, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). To date, anti-vascular endothelial growth factor (VEGF) treatment has been widely used to manage neovascular diseases associated with retinal ischemia. Nonetheless, a substantial number of patients with DR or AMD still suffer from incomplete response and adverse effects related to its therapy with limitations. Therefore, research scientists have been developing and finding novel treatments to protect against or prevent vision loss in those diseases. In this review article, we summarize the recent novel therapeutic approaches for the treatment of ischemic retinopathy (e.g., cell therapy, advanced molecular targeting, or drug delivery). This summary enables further research to obtain more solid evidence of novel effective drug development in retinal ischemic diseases. Full article

This study investigated the differential impact of two visual dimensions (direction and spatial location) in two spatial Stroop tasks, where the relevant dimension for the response varied. Three studies compared the interactions between spatial compatibility and congruence effects on reaction time performances to infer how the dorsal pathway (DP) and ventral pathway (VP) of visual processing interfered with one another in processing relevant and irrelevant spatial information. This allowed us to bridge neurophysiological mechanisms with dual-process models of spatial compatibility. The participants responded from an avatar’s perspective, manipulated through rotations relative to the forward position, along with independent rotations of the avatar’s screen and keyboard. The results revealed two distinct response patterns: in the Direction Stroop, the performance was influenced equally by the relevant direction (VP) and the automatic processing of irrelevant location (DP); in the Location Stroop, the VP exerted minimal interference on the DP. Furthermore, the Only Keyboard rotation disrupted hand–eye coordination, modulating the DP interference on the VP in the Direction Stroop. These findings provide insights into the functional interaction of these visual pathways and their contributions to spatial compatibility effects, along with evidence for the dual-process model of spatial compatibility. Some issues about the separation of visual pathways are discussed based on our results. Full article

This study assesses the accuracy and consistency of a commercially available large language model (LLM) in extracting and interpreting sensitivity and reliability data from entire visual field (VF) test reports for the evaluation of glaucomatous defects. Single-page anonymised VF test reports from 60 eyes of 60 subjects were analysed by an LLM (ChatGPT 4o) across four domains—test reliability, defect type, defect severity and overall diagnosis. The main outcome measures were accuracy of data extraction, interpretation of glaucomatous field defects and diagnostic classification. The LLM displayed 100% accuracy in the extraction of global sensitivity and reliability metrics and in classifying test reliability. It also demonstrated high accuracy (96.7%) in diagnosing whether the VF defect was consistent with a healthy, suspect or glaucomatous eye. The accuracy in correctly defining the type of defect was moderate (73.3%), which only partially improved when provided with a more defined region of interest. The causes of incorrect defect type were mostly attributed to the wrong location, particularly confusing the superior and inferior hemifields. Numerical/text-based data extraction and interpretation was overall notably superior to image-based interpretation of VF defects. This study demonstrates the potential and also limitations of multimodal LLMs in processing multimodal medical investigation data such as VF reports. Full article

Glaucoma is a visual disease that affects millions of people, and early diagnosis can prevent total blindness. One way to diagnose the disease is through fundus image examination, which analyzes the optic disc and cup structures. However, screening programs in primary care are costly and unfeasible. Neural network models have been used to segment optic nerve structures, assisting physicians in this task and reducing fatigue. This work presents a methodology to enhance morphological biomarkers of the optic disc and cup in images obtained by a smartphone coupled to an ophthalmoscope through a deep neural network, which combines two backbones and a dual decoder approach to improve the segmentation of these structures, as well as a new way to combine the loss weights in the training process. The models obtained were numerically evaluated through Dice and IoU measures. The dice values obtained in the experiments reached a Dice of 95.92% and 85.30% for the optical disc and cup and an IoU of 92.22% and 75.68% for the optical disc and cup, respectively, in the BrG dataset. These findings indicate promising architectures in the fundus image segmentation task. Full article

Background/Objectives: This paper aims to assess ChatGPT’s performance in answering European Board of Ophthalmology Diploma (EBOD) examination papers and to compare these results to pass benchmarks and candidate results. Methods: This cross-sectional study used a sample of past exam papers from 2012, 2013, 2020–2023 EBOD examinations. This study analyzed ChatGPT’s responses to 440 multiple choice questions (MCQs), each containing five true/false statements (2200 statements in total) and 48 single best answer (SBA) questions. Results: ChatGPT, for MCQs, scored on average 64.39%. ChatGPT’s strongest metric performance for MCQs was precision (68.76%). ChatGPT performed best at answering pathology MCQs (Grubbs test p < 0.05). Optics and refraction had the lowest-scoring MCQ performance across all metrics. ChatGPT-3.5 Turbo performed worse than human candidates and ChatGPT-4o on easy questions (75% vs. 100% accuracy) but outperformed humans and ChatGPT-4o on challenging questions (50% vs. 28% accuracy). ChatGPT’s SBA performance averaged 28.43%, with the highest score and strongest performance in precision (29.36%). Pathology SBA questions were consistently the lowest-scoring topic across most metrics. ChatGPT demonstrated a nonsignificant tendency to select option 1 more frequently (p = 0.19). When answering SBAs, human candidates scored higher than ChatGPT in all metric areas measured. Conclusions: ChatGPT performed stronger for true/false questions, scoring a pass mark in most instances. Performance was poorer for SBA questions, suggesting that ChatGPT’s ability in information retrieval is better than that in knowledge integration. ChatGPT could become a valuable tool in ophthalmic education, allowing exam boards to test their exam papers to ensure they are pitched at the right level, marking open-ended questions and providing detailed feedback. Full article

The ability to adopt different perspectives, or vantage points, is fundamental to human cognition, affecting reasoning, memory, and imagery. While the first-person perspective allows individuals to experience a scene through their own eyes, the third-person perspective involves an external viewpoint, which is thought to demand greater cognitive effort and different neural processing. Despite the frequent use of perspective switching across various contexts, including modern media and in therapeutic settings, the neural mechanisms differentiating these two perspectives in visual imagery remain largely underexplored. In an exploratory fMRI study, we compared both activation and task-based functional connectivity underlying first-person and third-person perspective taking in the same 26 participants performing two spatial egocentric imagery tasks, namely imaginary tennis and house navigation. No significant differences in activation emerged between the first-person and third-person conditions. The network-based statistics analysis revealed a small subnetwork of the early visual and posterior temporal areas that manifested stronger functional connectivity during the first-person perspective, suggesting a closer sensory recruitment loop, or, in different terms, a loop between long-term memory and the “visual buffer” circuits. The absence of a strong neural distinction between the first-person and third-person perspectives suggests that third-person imagery may not fully decenter individuals from the scene, as is often assumed. Full article

Eye tracking technology plays a crucial role in various fields such as psychology, medical training, marketing, and human–computer interaction. However, achieving high accuracy over a larger field of view in eye tracking systems remains a significant challenge, both in free viewing and in a head-stabilized condition. In this paper, we propose a simple approach to improve the accuracy of video-based eye trackers through the implementation of linear coordinate transformations. This method involves applying stretching, shearing, translation, or their combinations to correct gaze accuracy errors. Our investigation shows that re-calibrating the eye tracker via linear transformations significantly improves the accuracy of video-based tracker over a large field of view. Full article

Visuo-spatial attention acts as a filter for the flood of visual information. Until recently, experimental research in this area focused on neural dynamics of shifting attention in 2D space, leaving attentional shifts in depth less explored. In this study, twenty-three participants were cued to attend to one of two overlapping random-dot kinematograms (RDKs) in different stereoscopic depths in a novel experimental setup. These RDKs flickered at two different frequencies to evoke Steady-State Visual Evoked Potentials (SSVEPs), a neural signature of early visual stimulus processing. Subjects were instructed to detect coherent motion events in the to-be-attended-to plane/RDK. Behavioral data showed that subjects were able to perform the task and selectively respond to events at the cued depth. Event-Related Potentials (ERPs) elicited by these events—namely the Selection Negativity (SN) and the P3b—showed greater amplitudes for coherent motion events in the to-be-attended-to compared to the to-be-ignored plane/RDK, indicating that attention was shifted accordingly. Although our new experimental setting reliably evoked SSVEPs, SSVEP amplitude time courses did not differ between the to-be-attended-to and to-be-ignored stimuli. These results suggest that early visual areas may not optimally represent depth-selective attention, which might rely more on higher processing stages, as suggested by the ERP results. Full article

Discomfort is one of the leading causes associated with contact lens dropout. This study investigated changes in the tear film parameters induced by lens wear and their relationship with ocular symptomology. Thirty-four lens wearers (32.9 ± 9.1 years, 7 men) and thirty-three non-lens wearers (29.4 ± 6.8 years, 12 men) participated in this clinical setting. Subjects were categorised into asymptomatic (n = 11), moderate (n = 15), or severe symptomatic (n = 8). Clinical evaluations were performed in the morning, including blink frequency and completeness, pre-corneal (NIBUT) and pre-lens non-invasive break-up (PL-NIBUT), lipid interference patterns, and tear meniscus height. Contact lens wearers had a higher percentage of incomplete blinks (37% vs. 19%, p < 0.001) and reduced tear meniscus height compared to controls (0.24 ± 0.08 vs. 0.28 ± 0.10 mm, p = 0.014). PL-NIBUT was shorter than NIBUT (7.6 ± 6.2 vs. 10.7 ± 9.3 s. p = 0.002). Significant statistical differences between the groups were found in the PL-NIBUT (p = 0.01) and NIBUT (p = 0.05), with asymptomatic recording higher times than symptomatic. Long-term use of silicone–hydrogel lenses can affect tear stability, production, and adequate distribution through blinking. Ocular symptomology correlates with tear stability parameters in both lens wearers and non-wearers. Full article

Persistent corneal epithelial defects (PCEDs) are a challenging ocular condition characterized by the failure of complete corneal epithelial healing after an insult or injury, even after 14 days of standard care. There is a lack of therapeutics that target this condition and encourage re-epithelialization of the corneal surface in a timely and efficient manner. This review aims to provide an overview of current standards of management for PCEDs, highlighting novel, emerging treatments in this field. While many of the current non-surgical treatments aim to provide lubrication and mechanical support, novel non-surgical approaches are undergoing development to harness the proliferative and healing properties of human mesenchymal stem cells, platelets, lufepirsen, hyaluronic acid, thymosin ß4, p-derived peptide, and insulin-like growth factor for the treatment of PCEDs. Novel surgical treatments focus on corneal neurotization and limbal cell reconstruction using novel scaffold materials and cell-sources. This review provides insights into future PCED treatments that build upon current management guidelines. Full article

Vision Science is an area of study that focuses on specific aspects of visual perception and is conducted mainly in the restricted and controlled context of laboratories. In so doing, the methodological procedures adopted necessarily reduce the variables of natural perception. For the time being, it is extremely difficult to perform psychophysical, neurophysiological, and phenomenological experiments in open scenery, even if that is our natural visual experience. This study discusses four points whose status in Vision Science is still controversial. Namely, the copresence of distinct visual phenomena of primary and secondary processes in natural vision; the role of visual imagination in seeing; the factors ruling the perception of global ambiguity and enigmatic and emotional atmosphere in the visual experience of a scene; and if the phenomena of subjective vision are considered, what kind of new laboratories are available for studying visual perception in open scenery. In the framework of experimental phenomenology and the use of pictorial art as a complement and test for perceptual phenomena, a case study from painting showing the copresence of perceptual and mental visual processes is also discussed and analyzed. This has involved measuring color and light in specific zones of the painting chosen for analysis, relative to visual templates, using Natural Color System notation cards. Full article

Visual conditions significantly influence fear of movement (FOM), which is a condition that impairs postural control and quality of life (QOL). This study examined how visual conditions influence sway velocity during repeated one-leg standing tasks and explored the potential relationship between postural control, FOM, and QOL in older adults with and without FOM. Thirty-seven older adults with FOM and 37 controls participated in the study. Postural sway velocity was measured across three repeated trials under visual conditions in both anteroposterior (AP) and mediolateral (ML) directions. The groups demonstrated significant interaction under visual conditions (F = 7.43, p = 0.01). In the eyes-closed condition, the FOM group exhibited faster ML sway velocity than the control group, with significant differences across all three trials. There was a significant interaction between sway direction and vision (F = 27.41, p = 0.001). In addition, the FOM demonstrated strong negative correlations with several QOL measures on social functioning (r = −0.69, p = 0.001) and role limitations due to emotional problems (r = −0.58, p = 0.001) in the FOM group. While FOM influenced sway velocity during balance tasks, visual input emerged as a key determinant of postural control. The FOM group demonstrated a heightened reliance on vision, suggesting an increased need for vision-dependent strategies to maintain balance. Full article

Texture regularity, for example, the repeating pattern of a carpet, brickwork, or tree bark, is a ubiquitous feature of the visual world. The perception of regularity has generally been studied using multi-element textures whose regularity is manipulated by the addition of random jitter to the elements’ nominal positions. Here, we investigate the selectivity of regularity perception for the luminance contrast polarities of the elements. Our psychophysical tool was simultaneous regularity contrast, or SRC, the phenomenon in which the perceived regularity of a central test texture is shifted away from that of the surrounding regularity. Stimuli were composed of arrays of dark and/or white Gaussian elements. Surround and center test textures consisted of either the same (“congruent”) or opposite (“incongruent”) polarities. In addition, we tested a “mixed” condition consisting of a random mixture of polarities in both the surround and test. The perceived regularity of the test was measured using a match stimulus with the same polarity dimension as the test. The regularity of the match stimulus was adjusted on each trial using a forced-choice staircase procedure and the point-of-subjective equality between the match and test regularities was estimated from the resulting psychometric functions. SRC was observed in both congruent and incongruent conditions, but with the mixed condition, the perceived regularity of the test was shifted toward rather than away from the surround regularity, an example of assimilation, not contrast. The analysis revealed no significant difference in the magnitude of SRC between the congruent and incongruent conditions, suggesting that SRC could be mediated solely by polarity agnostic mechanisms, although there are other possible explanations for the “null” result. However, trend analysis using a non-linear (sigmoidal-shaped) function indicated a significant difference between the congruent and incongruent conditions, which, together with the mixed polarity results, suggests the presence of at least some polarity selective mechanisms. Previous reports have suggested that regularity perception is encoded by the “peakedness” in the distribution of spatial-frequency-tuned linear filter responses. We modelled SRC quantitatively by incorporating peakedness with spatial-frequency-selective surround inhibition and found that the model gave a good account of the SRC data. Possible reasons for the assimilation effect—with the mixed polarity condition are discussed. Full article

Recent advancements in head-up-displays have increased the number of instances where the visual system may face a different accommodative demand for each eye. A limited number of studies on aniso-accommodation exist, reporting contradictory results. We tested the natural capacity of observers to aniso-accommodate anisometropic stimuli. A dichoptic task allowed us to account for certain confounds, including high-level accommodation control. A 2AFC visual task was used, where participants judged if two overlapping sinusoidal gratings, presented dichoptically, had the same orientation. The gratings’ spatial frequency could be 1, 4 or 10 c/deg. The accommodative demand for each eye could be independently set to 2D or 4D. The accommodative response for each eye was recorded using an autorefractometer. Higher spatial frequencies and anisometropy had a negative impact on task accuracy. Contrary to expectations, spatial frequencies had no significant impact on accommodation response. The accommodation response to anisometropic stimuli was equal in the two eyes and leaned toward the lower of two demands. Our results confirm that when presented with asymmetrical accommodation demand, the two eyes tend to keep the same refractive power even in a dichoptic-requiring task. They also contradict the guidance of accommodation by spatial frequency in sinusoidal gratings. The visual task provided an objective measure of subjects’ performance, allowing for these conclusions to be drawn. Full article

Background: This research was conducted to study changes in iris microcirculation using optical coherence tomography angiography (OCTA) in patients with primary open-angle glaucoma after selective laser trabeculoplasty (SLT). Methods: All patients received standard SLT. OCTA examination of the iris was performed before SLT and one day and seven days after SLT using RTVue-XR with a 3 mm scan pattern and follow-up function. Iris vascularity was calculated with ImageJ software (version 1.53k) as vessel density on binarized images. Correlation between absolute or percentage changes in iris vessel density and intraocular pressure (IOP) changes was calculated. Results: A total of 31 eyes (31 patients, 10 females, 70.7 ± 8.9 years) were included. Iris vessel density increased statistically significantly (p = 0.002) the day after SLT followed by a decrease to baseline level at one week. A statistically significant correlation (r = 0.57, p = 0.002) was found between the percentage change in iris vessel density the day after the procedure and IOP change at three months. Conclusion: SLT is associated with a transitory increase in iris vessel density, which can be observed with OCTA the day after the procedure. Substantial increase in iris vascularity is associated with a poorer IOP-lowering effect of SLT in eyes with open-angle glaucoma. Full article

Eyes with maculopathy usually have poor fixation stability (FS) and develop a new preferred retinal locus (PRL). The exact FS and PRL have never been studied in diabetic macular ischemia (DMI). In this one-year observational study, we recruited 79 patients (145 eyes) with evidence of DMI on optical coherence tomography angiography (OCTA). Microperimetry (MP) was performed at baseline and 52 weeks. Overall, DMI eyes demonstrated relatively stable FS without evolving into eccentric fixation over one year. When comparing the better-seeing eye (BSE) with the worse-seeing eye (WSE) in eyes with bilateral DMI, the latter presented with a larger bivariate contour ellipse area (BCEA) initially but gradually aligned with the one in the BSE at the end of the study. Conversely, the foveolar retinal sensitivity (RS) worsened significantly alongside the extension of disorganization of the retinal inner layers (DRIL) in the WSE at one year despite the best-corrected visual acuity (BCVA) being maintained. This suggests that foveolar RS might reflect the start of DMI deterioration more sensitively than BCVA. Full article

Paracentral acute middle maculopathy (PAMM) is a macular condition primarily detected using optical coherence tomography (OCT) imaging. It presents as hyperreflective bands within the inner nuclear layer (INL) of the retina, often leading to localized degenerative phenomena. PAMM is a condition that reveals a dysfunction in the microvascular network of the retina. However, it is not an isolated phenomenon but rather an indicator of deeper and even systemic, prevalently vascular-related issues related to a wide array of conditions that impact circulation, including retinal vein and artery occlusion, diabetic retinopathy, and hypertensive retinal vascular changes. PAMM occurs due to impaired perfusion within the retinal deep capillary plexus, clinically leading to subtle but noticeable blind spots (scotomas) in the central visual field. Recent advances in imaging technology, particularly optical coherence tomography angiography (OCTA), have provided a clearer view of the underlying vascular alterations. Thus, PAMM may currently serve as a biomarker in broader ocular and systemic pathologies before disease progression. This review explores the latest reports in the literature on PAMM, from its characteristic imaging features to the evolving theories behind its development. By bridging the gap between ophthalmology and systemic health, PAMM may facilitate earlier diagnosis and tailored management strategies for conditions that extend far beyond the eye. Understanding this entity could ultimately transform our approach to assessing vascular health toward further research, risk prediction, and patient care. Full article