There are multiple presentations of ocular complications resulting from and occurring alongside COVID-19. These can further be classified as ocular complications and confirmed ocular diseases.

There have been a limited number of reports on the ocular manifestations of COVID-19, and more research is needed to fully understand the relationship between the virus and the eyes. However, some examples of the reported ocular manifestations include the following:

Conjunctivitis and other inflammations of eyes’ outer layers: Considering all cases of COVID-19 disease, conjunctivitis was reported in 5-9% of cases, episcleritis in 2.2% of cases, keratitis in 0.5% of cases, and blepharitis or lid margin hyperemia in 5% of cases. Concerning the physiological mechanisms that occur during infection, these COVID-19-related ocular manifestations have been suggested to result from a direct impact of the virus on ocular tissues ^[1][2][38,39]. One study found that conjunctivitis was present in 1.1% of hospitalized COVID-19 patients ^[3][40]. Another study found that conjunctivitis was present in 3.6% of COVID-19 patients in China ^[4][41].

Epiphora (excessive tearing): A case report described a patient with COVID-19 who experienced epiphora in one eye, which resolved after treatment with antiviral medication. Another study by Scalinci and Trovato described epiphora as a manifestation of conjunctivitis in COVID-19 patients ^[5][42].

Dry Eye: Dry eye disease was reported in high rates among subjects affected by COVID-19 disease. School-based research revealed a preponderance of dry eye as measured with a validated paper-based instrument ^[6][43]. Female gender and being of an older age were indicated as exacerbating risk factors ^[7][44]. A theoretical explanation was proffered to be the increased screen time during the pandemic period. Diskmetas et al. also showed a correlation between mask use and reduced tear break-up time during the heat of the pandemic ^[8][45]. Researchers suggested that dry eye in itself was an epidemic during the COVID-19 pandemic ^[9][46].

Eye pain: COVID-19 sufferers may experience eye discomfort as a dull aching, soreness, or a sense of pressure. It is thought to be caused by viral infection-induced inflammation of the conjunctiva (conjunctivitis) or other ocular tissues. Several research and case reports have established the existence of ocular discomfort in COVID-19 instances. For example, Wu et al. discovered that roughly 12% of COVID-19 patients exhibited ocular symptoms such as eye discomfort ^[3][40]. Also, a case report described a patient with COVID-19 who experienced eye pain, which was relieved with topical steroids ^[10][47]. These findings imply that eye discomfort may be an additional manifestation of COVID-19, emphasizing the necessity of evaluating ocular symptoms in the disease’s diagnosis and therapy. More study is needed to thoroughly understand the underlying causes and incidence of ocular discomfort in COVID-19 individuals.

Photophobia: A few case reports have described COVID-19 patients who experienced photophobia ^[3][5][40,42].

Retinal changes: Retinal ganglion cells and plexiform layers were shown to have characteristic lesions when analyzed by ocular coherence tomography in a Brazilian study of 11 COVID-19 patients ^[11][48]. These findings mirrored animal model studies that reported similar changes ^[12][49].

It is worth noting that these ocular manifestations are relatively rare, and COVID-19 primarily affects the respiratory system. In most cases, the ocular symptoms linked to COVID-19 in children tend to have a mild course, and complete visual recovery is typical ^[13][50]. However, healthcare professionals should be aware of the potential ocular manifestations of the virus, particularly in patients who present with eye symptoms and have a history of exposure to COVID-19.

Dry eye diseases are the most common reported ocular complications of COVID-19 ^[14][51]. Krolo et al. reported that face mask use was related to higher ocular surface disease index (OSDI) scores ^[7][44]. Other possible reasons may include increased screen time occasioned by working from home and inability to obtained needed dry eye medications due to the lockdown ^[15][52].

Children with COVID-19 have been reported to present with a largely self-limiting vasculopathy akin to the Kawasaki disease ^[16][53]. The pathological and clinical manifestations of this disease include conjunctivitis, keratitis, intermediate uveitis, and inflammation of the optic nerve head ^[17][54].

Reyes-Bueno et al. detailed the post-COVID-19 Miller Fisher syndrome (MFS) reported in some patients which included complaints of blurred vision and extra-ocular muscle palsy ^[18][55]. Neophytou et al. published a systematic review of this syndrome in COVID-19 patients with a conclusion that the condition occurred more frequently after infection as compared to after vaccination ^[19][56]. The prognosis of MFS is spontaneous and very good even without administering intravenous immunoglobulin ^[19][56].

Generally, viral diseases are directly linked to reduction in CD4+ and CD8+ counts. This in turn has been implicated in the incidence and reoccurrence of diseases such as her-pes-zoster ophthalmicus, infection induced uveitis and infective cellulitis ^[20][57].

Standard global precautions were advocated worldwide to stem the spread of the disease at the onset of the pandemic, including handwashing ^[21][58], using face masks ^[22][59], social distancing ^[23][60], coughing into the elbow ^[24][61], etc. Face masks with breath shields were found to reduce cough droplet spread by 99.98% in an eye care setting ^[25][62]. This was in comparison to breath shields alone, which reduced cough droplet propagation by 99.93% as compared to coughing without any protective barrier. ALBalawi reviewed clinical guidance from various regulatory bodies on the safe re-opening of eye hospitals after the lockdown ^[26][63]. He advocated a system similar to what Repici et al. ^[27][64] recommended, namely classifying patients as shown in Table 1.

Cornea surgery policies were also updated to reflect that surgery be stopped for patients presenting with an intermediate to high risk of COVID-19 exposure ^[30][67]. This was even as COVID-19 had been isolated from the corneas of infected patients ^[31][68].

Contact lenses are common optical devices used mainly in the correction of ametropia amongst others. Reports published have suggested that users transition from contact lenses to spectacle lenses to prevent hand-to-eye contact ^[32][33][69,70]. Furthermore, glasses can be a barrier to airborne viruses ^[34][71].

Telemedicine and artificial intelligence (AI) became increasingly important in ophthalmology, as well as other medical specialties. Technology advancements have enabled the development and use of new methodologies and approaches, allowing ophthalmologists to offer eye care and give ophthalmology education and training to patients remotely in specific scenarios ^[35][36][72,73]. Telemedicine and teleophthalmology in particular involve massive investments in diagnostic equipment and personnel who interpret these results ^[37][74].