Wednesday, 30 May 2018

Using a novel ocular injection platform to deliver drug to the suprachroidal space (SCS) at the back of the eye, Clearside Biomedical (NASDAQ:CLSD) is relentlessly pursuing treatments for blinding diseases with a late-stage pipeline for macular edema associated with uveitis and retinal vein occulusion and DME, as well as an early development program for wet AMD.
Drug delivery to the SCS has the potential to offer more optimal therapy through high bioavailability, even and efficient distribution throughout the eye, and rapid onset, with a better side effect profile,” president and CEO, Daniel White, says in an interview with BioTuesdays.
“The objectives of our program are rapid vision gains, sustained better vision, fewer injections and an improved benefits-to-risk ratio consistent across all patients, using the SCS microinjection.
Last month, Clearside launched a $36-million stock offering and granted underwriters an over-allotment option to sell an additional 600,000 shares at $9 each. Proceeds will be used for its clinical trial program with Zuprata and axitinib. Clearside also was added to the NASDAQ Biotechnology Index in mid-December.

Mr. White says a pivotal Phase 3 trial is underway treating uveitis patients, with data expected in the second half this year or early 2018 and a Phase 3 trial is being initiated with RVO patients. In addition, a Phase 1/2 study is underway in DME and the company expects to file an IND for the treatment of wet AMD in the first half this year.
“We estimate that there are nearly five million people in the U.S. diagnosed with non-infectious uveitis, RVO, DME and wet-AMD, which are the back-of-the-eye diseases we target,” he adds. Some 1,700 retinal specialists treat these patients. “Our intent is to establish a commercial infrastructure with an estimated sales force of 35-to-45 people to reach these specialists.”

Mr. White explains that administration of corticosteroids is the most common treatment for all symptoms of uveitis, including macular edema. There are some 350,000 uveitis patients in the U.S., of which 33%, or 115,000 people, have macular edema, a build-up of fluid in the macula, which causes the macula to swell and thicken, resulting in distorted vision.
In an earlier Phase 2 study in 22 uveitis patients with macular edema, Zuprata achieved a statistically significant reduction in retinal thickness as well as improvements in Best Corrected Visual Acuity (BCVA) on average 2 lines of improvement.

In addition, there were no serious adverse events related to treatment or discontinuation of the study as well as no steroid-related increase in intraocular pressure.
The ongoing six-month Phase 3 study in uveitis is expected to recruit 150 patients at 50 clinical sites, with 90 patients receiving Zuprata and 60 receiving a sham injection. The primary endpoint is superiority of BCVA from treatment.

According to Mr. White, macular edema is the most common cause of vision loss for patients following RVO and affects some 2.2 million people in the U.S. First line treatment is 10-to-12 annual anti-VEGF injections of Eylea, Lucentis and/or off-label Avastin.
Anti-VEGF drugs work by stopping a protein called vascular endothelial growth factor (VEGF) produced by cells in the retina and leading to new blood vessel growth, which is a major problem in a number of eye diseases.

Steroids like fluocinolone and dexamethasone also appear to have a reasonable track record providing efficacy in DME subjects, but adverse events, like development of cataracts in certain patients often appear to compromise visual gains seen within the first few months

Thursday, 17 May 2018

Metalens combined with an artificial muscle - Recent trends 


Inspired by the human eye, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed an adaptive metalens, that is essentially a flat, electronically controlled artificial eye. The adaptive metalens simultaneously controls for three of the major contributors to blurry images: focus, astigmatism, and image shift.
The research is published in Science Advances.
"This research combines breakthroughs in artificial muscle technology with metalens technology to create a tunable metalens that can change its focus in real time, just like the human eye," said Alan She, a graduate student at SEAS and first author of the paper. "We go one step further to build the capability of dynamically correcting for aberrations such as astigmatism and image shift, which the human eye cannot naturally do."
"This demonstrates the feasibility of embedded optical zoom and autofocus for a wide range of applications including cell phone cameras, eyeglasses and virtual and augmented reality hardware," said Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS and senior author of the paper. "It also shows the possibility of future optical microscopes, which operate fully electronically and can correct many aberrations simultaneously."
The Harvard Office of Technology Development has protected the intellectual property relating to this project and is exploring commercialization opportunities.
To build the artificial eye, the researchers first needed to scale-up the metalens.
Prior metalenses were about the size of a single piece of glitter. They focus light and eliminate spherical aberrations through a dense pattern of nanostructures, each smaller than a wavelength of light.
"Because the nanostructures are so small, the density of information in each lens is incredibly high," said She. "If you go from a 100 micron-sized lens to a centimeter sized lens, you will have increased the information required to describe the lens by ten thousand. Whenever we tried to scale-up the lens, the file size of the design alone would balloon up to gigabytes or even terabytes."
To solve this problem, the researchers developed a new algorithm to shrink the file size to make the metalens compatible with the technology currently used to fabricate integrated circuits. In a paper recently published in Optics Express, the researchers demonstrated the design and fabrication of metalenses up to centimeters or more in diameter.
"This research provides the possibility of unifying two industries: semiconductor manufacturing and lens-making, whereby the same technology used to make computer chips will be used to make metasurface-based optical components, such as lenses," said Capasso.
Next, the researchers needed to adhere the large metalens to an artificial muscle without compromising its ability to focus light. In the human eye, the lens is surrounded by ciliary muscle, which stretches or compresses the lens, changing its shape to adjust its focal length. Capasso and his team collaborated with David Clarke, Extended Tarr Family Professor of Materials at SEAS and a pioneer in the field of engineering applications of dielectric elastomer actuators, also known as artificial muscles.
The researchers chose a thin, transparent dielectic elastomer with low loss -- meaning light travels through the material with little scattering -- to attach to the lens. To do so, they needed to developed a platform to transfer and adhere the lens to the soft surface.
"Elastomers are so different in almost every way from semiconductors that the challenge has been how to marry their attributes to create a novel multi-functional device and, especially how to devise a manufacturing route," said Clarke. "As someone who worked on one of the first scanning electron microscopes (SEMs) in the mid 1960's, it is exhilarating to be a part of creating an optical microscope with the capabilities of an SEM, such as real-time aberration control."
The elastomer is controlled by applying voltage. As it stretches, the position of nanopillars on the surface of the lens shift. The metalens can be tuned by controlling both the position of the pillars in relation to their neighbors and the total displacement of the structures. The researchers also demonstrated that the lens can simultaneously focus, control aberrations caused by astigmatisms, as well as perform image shift.
Together, the lens and muscle are only 30 microns thick.
"All optical systems with multiple components -- from cameras to microscopes and telescopes -- have slight misalignments or mechanical stresses on their components, depending on the way they were built and their current environment, that will always cause small amounts of astigmatism and other aberrations, which could be corrected by an adaptive optical element," said She. "Because the adaptive metalens is flat, you can correct those aberrations and integrate different optical capabilities onto a single plane of control."
Next, the researchers aim to further improve the functionality of the lens and decrease the voltage required to control it.
The research was co-authored by Shuyan Zhang and Samuel Shian. The research was supported in part by the Air Force Office of Scientific Research and by the National Science Foundation. This work was performed in part at the Center for Nanoscale Systems (CNS), which is supported by the National Science Foundation.

Tuesday, 8 May 2018

Improved Visual Efficiency with Dark Chocolate

There may be a common pathway between the visual perception improvements and the cardiovascular protective effect, namely the effect of plant molecules called polyphenols. The polyphenols found in cocoa are called flavanols. These have an especially positive effect on our blood vessels, by healing damage to the lining, relaxing the muscle, and improving blood flow. Studies have shown that cocoa flavanols also improve blood sugar metabolism and reduce the risk of developing diabetes, as well as reduce risk for heart and vascular disease in patients who have diabetes. The authors of the visual study hypothesize that cocoa flavanols enhance availability of oxygen and nutrients to the blood vessels of the eye and brain. The retina in particular, they point out, is very highly vascularized and may be the area of interest in these study findings.

Saturday, 5 May 2018

 Ocular Melanoma:

Perhaps you've heard of melanoma. It develops from the cells that produce the dark-colored pigment melanin, which is responsible for our skin's coloring. These cells, called melanocytes, are found in other places in our bodies, too: our hair, the lining of our internal organs, and our eyes. So while most melanomas do form on the skin, it is possible for a melanoma to form elsewhere. When it forms in the eye, it’s known as ocular melanoma or, more specifically, uveal melanoma.

OM is much rarer than skin melanoma and behaves quite differently. There are other types of eye cancers, but OM is the most common in adults and the most dangerous. It's a potentially lethal disease which many people die from, especially when it spreads to the liver, a complication in about half of people diagnosed with this disease.

No one knows for sure why OM tumors form but there is heightened prevalence amongst fair-skinned and blue-eyed individuals. Originally, excessive exposure to sunlight was thought to be a key risk factor but no study has proven a direct linkage to development of OM tumors.
OM tumors arise from the pigment cells (melanocytes) that give color to the eye. Formation of these tumors is quite rare and, as for many other forms of cancer, the exact cause is unknown. It is known that exposure to ultraviolet (UV) rays (either from the sun or sunbeds) increases the risk of developing melanoma of the skin. People whose skin burns easily are most at risk – people with fair skin, fair or red hair and blue eyes. However, there has no conclusive evidence linking UV exposure and OM.

Ocular melanoma may be more common in people who have atypical mole syndrome, which is also called dysplastic naevus syndrome. People with this condition have a greater risk of developing a melanoma of the skin, and often have over 100 moles on their body, some of which are abnormal in size and shape.

Current Scenario:

Approximately 2,500 adults are diagnosed with ocular melanoma every year. There is no known cause, though incidence is highest among people with lighter skin and blue eyes.

Approximately 50% of patients with OM will develop metastases by 10 to 15 years after diagnosis (a small percentage of people will develop metastases even later i.e. 20-25 years after their initial diagnosis). Metastatic disease is universally fatal. This 50% mortality rate is unchanged despite treatment advances in treating the primary eye tumor. More research is needed urgently to improve patient outcomes

Emerging techniques to eradicate OM:

  1. Transpupillary Thermotherapy
  2. Iridocyclectomy
  3. Trans-Sclera Local Resection
  4. Plaque Radiotherapy
  5. Trans-Retinal Endoresection.

Tuesday, 10 April 2018

STOP Concluding before Exploring

A new layer in the front layer of the human eye has been discovered by researchers at The University of Nottingham.2013

The layer has been called the "Dua's Layer", named after the researcher who led the study, Professor Harminder Dua. 

The cornea is located on the front of the eye and allows light to enter. Previously believed for made up of five different layers:
  • Bowman's layer
  • The corneal epithelium
  • The corneal stroma
  • Descemet's membrane
  • The cornel endothelium
The Dua's layer is located in the back of the cornea between the corneal stroma and Descemet's membrane.

 It is extremely tough and strong despite being only 15 microns thick, it also impervious to air.

The researchers say that corneal hydrops, a condition that occurs when water from inside the eye rushes in and leads to a fluid buildup in the cornea, is likely caused by a tear in the Dua layer. 

Monday, 26 March 2018


The trendy generation is addicted to the usage of the digital gadgets ,which is cited as the cause for their increased risk of visual disorders. It is common for the individuals to hold jobs as computer workers but people rely on these platforms for entertainment, news, and even social updates from friends.
In the current scenario 253 million people live with vision impairment and 36 million are blind and 217 million have moderate to severe vision impairment .It is usual to find that people t the age 50 have severe visual impairments and 81% of these age group becomes blind annually.
Apart from these issues,chronic eye diseases are the main reason for vision loss. The two main reasons for the vision impairment is reported as Uncorrected refractive errors and untreated cataract .Untreated cataract remains the leading cause of blindness in low- and middle-income countries. Yet by efforts and advancement in the field of Optometry and Vision Science have reduced more Ocular disorders and diseases. The infectious eye diseases, such as trachoma and onchocerciasis, have reduced significantly over the last 5years and sure that  about over80% of all vision impairment can be prevented or cured.

Importance and Scope:

Optometry 2018 will be International platform to share the Advancements in the field of optometry and the Vision Science.The new era begins with recent technologies making impossibles as possibles. The Ocular diseases effectively treated with Ocular Drug Delivery advances.The various perspectives regarding the Optometry are discussed

Why Rome?

Rome is the capital city of Italy,and has the population of about 2,688,000 within the area of 1502 sq km (580 sq mi).It is located inland about 27 kilometers (17 miles) from the Tyrrhenian Sea and has been serviced by  two international airports making it an attractive tourist spot.The latest figures indicate that close to 60 million people visit Italy every year. Romans consider social life and interaction as important feature as the success in business and social lives are all regarded more favorably than individual assertiveness. In the current scenario academic institutions and educational centers near Rome include Istituto Guglielmo Tagliacarne, Istituto Quasar Design school, John Cabot University, Pontifical Athanaeum Regina Apostolorum, Pontifical University of Saint Bonaventure, Pontifical University of St. Thomas Aquinas in Rome, and more. Istituto D’Istruzione Vittorio Alfieri Roma well reputed eye institue.

Why to attend?

Optometry 2018 put forwards the motto of sharing a wide knowledge by this gathering in the advancements and leads support to the well being of the patients and improved professional ethics for the professionals and lessening the constrains making the vision enlightened .

Major Associations around the world :

1) Federottica- optometry association in italy
2) The World Council of Optometry (WCO)
3) American Optometric Association (AOA)
4) The Association of Optometrists (AOP)
5) Optometrists Association Australia(OAA)
6) Indian Optometric Association (IOA)
7) The Association of Schools and Colleges of Optometry (ASCO)
8) National  Optometric Associations (NOA)
9) Michigan Optometric Associations (MOA)
10) Vision Sciences society(VSS)
11) Florida Optometric Association(FOA)
12) The Association for Research in Vision and Ophthalmology(ARVO)
13) The Association of Vision Science Librarians
14) Association For Ocular Pharmacology and Therapeutics (AOPT)
15) Kentucky Optometric Association(KOA)
16) Macular Degeneration Association (MDA)
17) International Glaucoma Association(IGA)
18) American Association for Pediatric ophthalmology(AAPO)
19) European Association for Vision and Eye Research(EVER)
20) Association for the Blind and Visually Impaired of Northern New York (ABVINNY)
21) The International Council of Ophthalmology(ICO)
22) American Ophthalmological Society(AOS)
23) European Society of Ophthalmology(SOE)
24) The International Agency for the Prevention of Blindness-IAPB
25) Retina France Associations(RFA)
26) European Society of Cataract &Refractive Surgeons(ESCRS)
27) European Society Of Ocular and Surface Disease Specialists(EuCornea)
28) International Society of Ocular Trauma(ISOT)

Top Universities in Italy

1. University of Florence
2. University of Milano-Bicocca[38]
3. University of Padua, Italy [39]
4. University of Naples Federico II
5. University of Roma Tre
6. University of Salento[40]
7. University of Turin

Optometric Market Value in Italy:

Revenue from Optical  market  generated  amounts to US$7,112m in 2018. The market is expected to grow annually by 0.8 %. Considering the total population figures, per person revenues of US$117.67 are obtained in 2018.

Blindness Caused by the Ocular Diseases:
The causes of blindness are reported is analyzed  as expected, POAG was the main cause , whereas PACG accounted for rare cases. Glaucoma patients frequently had other eye diseases determining blindness high myopia , retinal detachment , and corneal defects . When the analysis was targeted to eyes that converted to blindness during the study, similar data were found with the exception of a lower prevalence of trauma, retinal degeneration and corneal defects.this analysis also widely helped to evaluate frequency, conversion rate, and risk factors for blindness in glaucoma patients treated in European Universities. Blindness by glaucoma had two characteristics they are late diagnosis and  late referral, and progression of the disease despite in most cases. Yet the advancement  in glaucoma treatment could overcome these  issues.

Employment Growth for Optometrists:
Optometrist are previously known as opticians, they are trained to examine the eyes and detect defects in vision, signs of injury, ocular diseases or abnormality in eyes, caused by high blood pressure or diabetes. They offer clinical advice, prescribe contact lenses and refer patients for further treatment, when required.  Optometrists  should be a graduate of university for least three years and must indulge in  clinical training practices, before being deemed to have the knowledge and skills to be registered. As the field of Optometry has a wide growth it offers great opportunities for the optometrists. This line chart details the projected employment growth for Optometrist.This profession is expected to grow faster than 6.5% comparing other professions.

Scientific Sessions to be Discussed

The visual system is a model for  higher brain function studies.  The main two aspects of visual neuroscience are, the function of brain mechanisms that encoding information about the form, color, motion, and depth of visual objects and scenes and other that decoding this information to generate perceptual experience and visually-guided action.
Visually-Guided Gaze Behavior
Spectrum Sensitivity
Neural and Computational Models of Vision
Perception of Light and Shadows

Ocular biochemistry  details  in research on biochemical, immunological and genetic aspects of the eye diseases. Proteins that are  unique to the eye and have special functions in the eye, such as collagen's role in the structure of the cornea, emphasize the importance of these compounds and their ocular functions , lipids that exist in the eye ,neurochemistry etc are also discussed.
Biochemistry of Vision
Ocular Fluids
Metabolism of Cornea
Genetic basis of Retinoblastoma
 Wald’s Visual Cycle
 Photochemistry of Vision

Ocular pathology  related to  surgical pathology and also to ophthalmology which deals with the diagnosis and characterization of neoplastic and non-neoplastic diseases of the eyes. It is used to identify  the  pathological condition and also to understand the pathophysiology of the disease.
Thyroid Eye Disease
Mechanical Trauma
Corneal Dystrophies

Ocular microbiology details  advancements in molecular biology and pave way for better understanding of ocular diseases.  The field of infectious diseases are rapid, thus many opportunistic pathogenic agents are increasingly found in ocular infections due to widespread use of topical and systemic immunosuppressive agent. These opportunistic pathogens cause ocular infections due to continuous use of contact lens. The dreadful  cataract extraction and lens implantation often are mainly caused by these opportunistic pathogens.The acute infections of the external eye are caused by a vivid range of microbiological pathogens .
Bacterial Conjunctivitis
Viral Conjunctivitis
Dendritic Keratitis
A visual prosthesis  has the  significance of restoring of vision .It is achieved by stimulation of nerve fibers .  All retinal prostheses under development are intended to deliver electrical pulses on to the retina.  The retinal prosthesis will capture visual images using micro electronic prosthesis  and turn light energy into electrical pulses, and pass electrical pulses to the retina thus enabling the blind  to have vision. Visual prostheses could interface with the visual pathway at multiple locations.
Argus retinal prosthesis
Microsystem -based visual prosthesis (MIVP)
Implantable miniature telescope
Tübingen MPDA Project Alpha IMS
Harvard/MIT Retinal Implant
Artificial silicon retina (ASR)
Photovoltaic retinal prosthesis
Intracortical visual prosthesis

 It is comprehensive and composed with  ocular therapeutics. The basic pharmacology of drug delivery in the eye; systemic medications  with their indications and                                                                                                                contraindications. Medication-related adverse drug reactions (ADRs) - extra and intraocular muscles and Anti-infective drugs for primary eye care; Ophthalmic corticosteroids  are also managing  the ocular inflammatory response.
periocular injections
ocular drugs

Eradicating ocular melanoma is done by radiation and surgerical method. The common  radiation therapy used  to treat  ocular melanoma is called plaque radiation therapy.  A disk attached with radioactive seeds, called plaque is placed directly on the wall of the eye  lying next to the tumor. Treatment options will vary based on the location and size of the melanoma and health.  Melanoma on the eyesurface is treated with chemotherapy eye drops, freezing treatment, and radiation.   
Plaque Radiotherapy
Trans-Sclera Local Resection
Trans-Retinal Endoresection
Transpupillary Thermotherapy
The cornea is the protective outer layer of the eye. Corneal disease terms the condition that affect cornea of eye.  These include infections, tissue breakdown, and other disorders transfered from parents.  Eye diseases and injuries cause corneal damage.  Cornea is cone shaped rather than domeshaped in the Keratoconus and in Fuchs’ dystrophy the cells in the inner layer of the cornea are malfunctioning.
Inflammatory corneal disease.
Neurotrophic  Keratitis
Cornea Ulcer
Autologous serum
Amniotic membrane transplantation

Glaucoma is a disease which damages the eye’s optic nerve. It happens when fluid builds up in the front part of the eye.  That extra fluid present increases the pressure in the eye, damaging the optic nerve. In recent years  there has been  new surgical advances in glaucoma surgery.  The XEN Gel Stent , a hybrid between traditional glaucoma surgery and  invasive glaucoma surgery.  Implanted ab interno through a clear cornea incision  creates a bleb by shunting fluid from the anterior chamber to  subconjunctival space.
Pigmentary Glaucoma
Pseudoexfoliative Glaucoma
Traumatic Glaucoma
Neovascular Glaucoma
Irido Corneal Endothelial Syndrome (ICE)
Uveitic Glaucoma
XEN Gel Stent
Punctual Plug Delivery

Orthokeratology is shortened as "ortho-k" and called corneal reshaping (CR) or corneal refractive therapy.  Orthokeratology refers to usage of gas permeable contact lenses that reshape the cornea and reduces refractive errors such as myopia, hyperopia and astigmatism.  New ortho-k lens designs are available for farsightedness and presbyopia.  Research also stated that orthokeratology lens designs slowers the progression of myopia.
 Corneal Refractive Therapy
Myopia Control
Corneal Reshaping

The unique products  have to be different from what the big-box stores offer.  Price doesn't be an issue with unique products, they gain the value back  because they are harder to find .  The successful Optometrists are those who surround themselves  with an Accountant, Lawyer and Banker.  These industry experts help when making key decisions, like buying an existing practice or financing a new, practice valuation, loan structure and industry trends that might affect future decisions, so the solid planning is  important . Opening a new Optometry practice is a risky but a rewarding venture.  The market stratergies are changing with upcoming innovations and focuses on the reaching the higher standards.
innovations in optometric appliances
value chain concept
ECP patient marketing
profit model strategies

  The damage to photoreceptor cells of the retina is known as the retinal degeneration. The photoreceptor cells are the light sensing cells in the retina, a delicate nerve layer that lines  behind the eye.  The  photoreceptor cells absorb the light  and  initiate a continuous electrical impulses that are sent through the retina via optic nerve to the brain and create an image.  When the photoreceptor cells malfunctions due to the degenerative disease, the image received is  distorted or completely unseen. The common retinal degenerative diseases are Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). The artificial retina is the current solution to this problem.
 Age Related Macular Degeneration
 choroidal neovascularization (CNV)
 Sorsby’s Fundus Dystrophy (SFD)

Vision science , an interdisciplinary study of visual systems and perception and includes many disciplines like optometry, ophthalmology, molecular genetics, neuroscience and physiological optics. The vision science details in the study of vision from the perspectives of computer science, cognitive psychology and psychophysics. The advancement is improving the human visual health , vision and action, visual crowding, visual masking, spatial vision, temporal sensitivity, flicker, optometry, ophthalmology, texture perception, classification image, reverse correlation, spatial uncertainty etc.
Visual Acuity and Visual Field
Visual Motor Abilities
Visual Perception
Ocular surgery  always progresses along the advancement of science advances.  New emerging technologies in laser enhance the surgeries. When the natural lens of your eye becomes cloudy due to age its known as  cataract.  It can be replaced with an artificial lens implant.  An ophthalmologist prefers surgical instruments and ultrasound power to  replace the eye's cloudy lens. The surgeons are dealing in such tiny spaces in the eye, they depend on  lasers not blades, for improved precision, though lasers have been used only for other eye surgeries, such as vision correction (LASIK) surgery.
Laser eye surgery.
Cataract surgery.
Glaucoma surgery.
Refractive surgery.
Corneal surgery.
Vitreo-retinal surgery.
Eye muscle surgery.

Ocular drug delivery was a milestone to pharmacologists  due to eye's unique anatomy and physiology. The clinical demand arises for the delivery of therapeutic molecules in the anterior and posterior parts of the eye. Conventional eye drops are used for the treatment of ocular low corneal penetration but has poor ocular bioavailability (5%). Hence biopolymers are preferred for the composite materials that  enhances the precorneal retention time, drug delivery control and induces the corneal absorption of drugs.
Scleral Buckling Materials
Capsular type
Retrometabolic delivery system
A visual testing of a patient's iris is to make a diagnosis.   Iris abnormalities caused  from trauma, infection, neoplasm and genetic reasons.  The iris  structure is composed of connective tissue and blood vessels that lies anterior to lens. The central opening of the iris denotes the pupil. The color of  iris is determined by pigmented cells  lies in the stroma. Pigment accumulate in these cells during the first year of life, and the color of  iris often changes during times. The posterior layer of  iris is deeply pigmented. It also extends slightly onto the anterior surface of the  pupil.
Heterochromia iridis
The  vision disorders are refractive errors, more commonly referred as nearsightedness, farsightedness, astigmatism and presbyopia.   When the shape of  eye prevents light from focusing directly on to retina leads to refractive errors . The eyeball length  ,corneal shape change , or lens aging causes refractive errors. Anisocoria is  characterized by an unequal   eyes' pupil size. Astigmatism is a vision condition that causes blurred vision occuring  when the cornea  is irregularly shaped and sometimes because of the curvature of the eye lens inside.
Black eye

Several diseases affect the eye, either directly or indirectly .  These conditions require urgent professional care to preserve the vision. The common types of the eye diseases are pink eyes,styes and chalazia etc. Pink eye  is an  infection of the transparent membrane that lines the eyelid and covers the white region of the eyeball. It iscommonly caused by the bacterial and viral infection, or an allergic reaction and it iscontagious.Styes and Chalazia ,two common conditions that affect the eyelids. A chalazion causes blockage of  the small oil producing glands (meibomian glands) that found in the upper and lower eyelids. Styes are infections or abscesses of the eyelid gland near an eyelash root or follicle.
 macular oedema
Children experience more changes in bodies and vision while growing.  Thus it is recommended  for testing the baby's eyes between ages 6 months to one year and especially if the child was born prematurely or it has a lazy eye or crossed eyes or there is a family history of eye disease. Once children reach three age, eye examinations should be conducted regularly.  Professional eye care is important part in the child's annual health care routine.  During first 12 years of life, 80 percent learning is through vision hence Vision problems detected early are more helpful to treat, and may avoid the need for glasses or a strong vision prescription.
autorefractive screening
visual evoked potential /response

Diagnostic imaging techniques  gains tremendous importance in the examining  ocular and orbital disease. The diagnostic imaging, with special focus directed toward the advanced modalities are important in evaluation of the traumatized eye.  Advances made in diagnostic and imaging techniques within the  years have revolutionized the field, and helps in management of many ophthalmic diseases.  The basic tools of refractive surgery are Wavefront and Optical Coherence Tomography (OCT).
Multimodal Imaging
Small Gauge Endoscopy
 Spectral-domain Optical Coherence Tomography
OCT Angiography

In the  visual cognition, high-level vision, mid-level vision and top-down processing  refers to decision-based scene analyses and combines prior knowledge with retinal input to create representations. This is the method by which the brain gets visual information and thus  it process information and its ability to recognize one's visual misconceptions and fufils the efforts to merge the knowledge gaps.
Scene Categorization
Visual Recognition

Optic neuropathy generally describes optic nerve abnormalities or damage, also including the causes as blocked blood flow and exposure to toxic.  The symptoms for optic neuritis can include blurring and blind spots and even distorted vision, reduced color vision and pain on the eye movements.  These types of symptoms may lead to vision loss due to optic neuritis.   Optic neuritis  occurs in adults younger than 45 and affects more on  women .  The common condition in people having multiple sclerosis (MS), where the nerve coverings are destroyed by the immune system.
 Ischemic Optic Neuropathy
Fourth Nerve Palsies
oblique myokymia