Myopia is a common eye condition when objects which are far appear blurry and objects closer appear to be clear. It is also called as near sightedness or short sightedness it’s one of the most common refractive conditions.

People with myopia can have difficulty clearly seeing a movie or TV screen, a whiteboard in school or while driving. Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes.

Amblyopia or 'lazy eye' — is a condition in which the eyes and brain don't work together as they should. Kids who have it will develop good vision in one eye and poor vision in the other. Kids often get used to this vision problem, and might not mention it to parents. As a result, their amblyopia might not be diagnosed for months or even years, while parents chalk up poor grades or clumsiness to a child not being academically or athletically gifted

A number of things can interfere with normal brain–eye connections and lead to amblyopia. Strabismus or crossed eyes, Shortsightedness or Myopia, Far Sightedness or Hyperopia,Astigmatism,An isometropia when one eye sees more clearly than the other

Regular vision screenings by health care providers are an important part of finding any problems in kids.

Hyperopia, or farsightedness, is a common vision problem affecting about a fourth of the population. People with hyperopia can see distant objects very well, but have difficulty focusing on objects that are up close. The condition is sometimes referred to as "hypermetropia" rather than hyperopia.

People with hypermetropia may have eyestrain,headaches,eye strain,blurred vision,in some instances, squints etc.

Astigmatism is a vision condition that causes blurred vision due to an irregularly shaped cornea, the clear front cover of the eye, and changes in curvature of the crystalline lens inside the eye.

In an astigmatic eye, the cornea or the crystalline lenses are not smooth or evenly curved thus focusing the light irregularly at different regions of the retina. If the cornea is not evenly curved it’s called corneal astigmatism and if the lenses are not curved regularly, it is called lenticular astigmatism.

Major symptoms are

• Blurring and distortion of near or far-away objects
• Headaches when trying to focus
• Tired eyes
• Eye discomfort

Astigmatism correction

• Eyeglasses - This is the most popular correction method for astigmatism and these eyeglasses have a special cylindrical lens prescription that corrects astigmatism.
• Contact lenses - Some people with an active lifestyle prefer astigmatism correction with contact lenses. Contact lenses may provide clear vision and a wider field of view. Special toric soft contact lenses can correct many types of astigmatism.

Keratoconus is an eye condition that affects the shape of the cornea, which is the clear outer covering of the eye. In this condition, the cornea thins and bulges outward, eventually resembling a cone shape. These corneal abnormalities, which worsen over time, can lead to nearsightedness (myopia), blurred vision that cannot be improved with corrective lenses (irregular astigmatism), and vision loss.

Keratoconus symptoms include

• Worsening of vision causing frequent changes to prescription
• Blurring or clouding of vision
• Sensitivity and glare from bright lights

During the early stages of keratoconus, the condition can usually be treated with contact lenses or glasses. RGP (rigid gas permeable) keratoconus contact lenses may be required to correct vision as the cornea becomes thinner and more irregular. In rare cases, a corneal transplant may be required, but there are now multiple keratoconus treatment options available that reduce the need for keratoconus surgery.

Glaucoma is one of the leading causes of blindness for people worldwide. But blindness from glaucoma can often be prevented if detected early. Initially, Glaucoma has few or no symptoms. Usually, Glaucoma is related to high eye pressure also called Intra Ocular Pressure (IOP). This high eye pressure causes damage to the Optic Nerve which is a structure on the back of the eye responsible for carrying millions of nerve fibers from the retina to the brain that helps sight.

If left untreated it can cause loss to peripheral vision which can lead to tunnel vision and eventually blindness. As it generally starts impacting the peripheral vision first, in many instances, the person suffering from Glaucoma is unable to realize the loss of vision

Blepharitis is an inflammation of the eyelids in which they become red, irritated and itchy with dandruff-like scales that form on the eyelashes. It is a common eye disorder caused by either bacteria or a skin condition, such as dandruff of the scalp or rosacea.

People with blepharitis may experience a gritty or burning sensation in their eyes, excessive tearing, itching, red and swollen eyelids, dry eyes or crusting of the eyelids. For some people, blepharitis causes only minor irritation and itching. However, it can lead to more severe symptoms, such as blurring of vision, missing or misdirected eyelashes, and inflammation of other eye tissue, particularly the cornea. By touching and rubbing the irritated area, a secondary infection can also result. If you develop these infections make sure you visit your eye doctor

cataract is clouding or opacity of the lens inside the eye. It causes gradual blurring of vision and often glare. In a normal eye this lens is clear. It helps focus light rays onto the back of the eye (the retina), which sends messages to the brain allowing us to see. When a cataract develops, the lens becomes cloudy and prevents the light rays from passing onto the retina. The picture the retina receives becomes dull and fuzzy. A cataract usually forms slowly and most people experience a gradual blurring of vision.

Cataracts generally form very slowly. Signs and symptoms of a cataract may include:

• Blurred or hazy vision.
• Reduced-intensity of colors.
• Increased sensitivity to glare from lights, particularly when driving at night.
• Increased difficulty seeing at night.
• Change in the eye's refractive error, or eyeglass prescription.

Colour blindness is a genetic disorder which occurs when the patient is unable to see colours in a normal way. It is also known as colour deficiency. Colour blindness often happens when someone cannot distinguish between certain colors. This usually happens between greens and reds, and occasionally blues.

The symptoms of color blindness can range from mild to severe. Many people have such mild symptoms that they are unaware that they have a color deficiency. Parents may only notice a problem with a child when he is learning his colors.

The symptoms include:

• trouble seeing colors and the brightness of colors in the usual way;
• inability to tell the difference between shades of the same or similar colors. This happens most with red and green, or blue and yellow.

There is no treatment for congenital color blindness. It usually does not cause any significant disability. However, there are special glasses ,that may help.

Presbyopia is the normal loss of near focusing ability that occurs with age. Most people begin to notice the effects of presbyopia sometime after age 40, when they start having trouble seeing small print clearly — including text messages on their phone.

When you become presbyopic, you either have to hold your smartphone and other objects and reading material farther from your eyes to see them more clearly.

Presbyopia can cause headaches, eye strain and visual fatigue that makes reading and other near vision tasks less comfortable and more tiring.

A pterygium is an abnormal growth of tissue that extends from the conjunctiva (a membrane that covers the white of the eye) onto the cornea. Pterygia may be small, or grow large enough to interfere with vision and cause irritation. These growths are commonly located on the inner corner of the eye.

At first, a pterygium might not have any symptoms but as it gets larger, the eye looks red, itchy or feels like there’s something in it a pink-colored growth on the eye may be noticed.

Conjunctivitis, also known as pink eye, occurs when the conjunctiva (the white part of the eyeball and the inner eye lid) is irritated by an infection or allergies. Conjunctivitis is highly contagious and can be caused by several different types of viruses and bacteria. It can occur with colds or symptoms of a respiratory infection, such as a sore throat.

Conjunctivitis can occur in one or both eyes.

Symptoms of conjunctivitis include:

• Redness
• Itchiness
• A gritty feeling
• Excessive tearing
• Discharge that forms a crust that may prevent your eye or eyes from opening in the morning.

A chalazion is a painless bump on your eyelid. It can affect the upper or lower eyelid. It is often confused with an eye stye ,but a chalazion is different in that.These cyst-like eyelid bumps form around an oil gland within the lid and can cause red, swollen eyelids.

Applying a warm compress to the area for 10-15 minutes and gently massaging the eyelids daily for a few minutes can help to soften oil blockages and effectively drain to the ducts. To prevent further discomfort, avoid touching the affected area once it starts to drain and ensure you keep it clean. Avoid wearing eye makeup and contact lenses throughout the chalazion healing stages. Typically it disappears without treatment within several weeks to a month, although they often recur.

When you open your eyes and see a single, clear image it’s the result of a complex process that requires the many parts of your vision to work together smoothly.

Double vision can occur with one eye or both. If it's in one eye when the other is closed, it is less worrisome, but still serious. If it occurs when both eyes are open, it could signal a major disorder.

People with double vision will see two images of one object at the same time. It might look like the images are side by side, overlapping, or a mixture of the two. Some people are affected only occasionally, but for others it can be a constant problem

Causes of double vision in one eye Double vision in one eye is known as monocular and is least common of the two. This type is usually caused by an eye problem, such as:

• Astigmatism
• Dry eye syndrome
• Cataracts
• Macular degeneration

As double vision can occur for a number of reasons, treatment will depend on its underlying cause, and could range from simple eye exercises to minor surgery.

Photophobia, or light sensitivity, is an intolerance of light. Sources suchas sunlight, fluorescent light and incandescent light can all cause discomfort, along with a need to squint or close your eyes. Headaches also may accompany light sensitivity.

Causes

• Dry eye, Uveitis (inflammation inside the eye),inflammation of the cornea, the clear layer at the front of the eye)
• Ocular albinism (a lack of pigment in the eye that affects the eye’s ability to block light coming into the eye)
• Cataracts (cloudy patches in the lens of the eye)
• Conjunctivitis (inflammation of the conjunctiva, the membrane that covers the eye)
• Damage to the retina, the light-sensitive layer in the back of your eye
• Blepharospasm (a condition that makes the eyelids close uncontrollably)
• Light sensitivity may also affect people with medical conditions that affect the nervous system, as well as some mental health conditions. They’re also a very common symptom in migraines

Treatment

Treatment for light sensitivity is to address the underlying cause. Once the triggering factor is treated, photophobia disappears in many cases.

A crossed eye or out-turned eye is referred to clinically as strabismus. It is a muscle condition in which your eyes are not properly aligned with each other, resulting in double vision or the suppression of the image from the affected eye. For a variety of reasons, one or both of your eyes may turn in, out, up or down.

Children with strabismus may initially have double vision. This occurs because both eyes are not focusing on the same object. In an attempt to avoid double vision, the brain will eventually disregard the image from one eye. This is referred to as suppression. In time, the ignored eye will become unable to function normally and will become largely unused. This may result in the development of lazy eye (amblyopia).

Tunnel vision is a lack or loss of peripheral vision that only allows you to see objects directly in front of you. You can simulate severe tunnel vision by covering one eye and using the other to look through the cardboard tube of a roll of paper towels.

Often, peripheral vision loss that leads to tunnel vision occurs gradually. By the time you realize you no longer have a normal field of view, your tunnel vision may already be permanent and irreversible.

The most common cause of tunnel vision and peripheral vision loss is damage to the optic nerve caused by glaucoma.

Other potential causes include Eye strokes,Retinal detachment,Retinitis pigmentosa,Optic neuritis etc.

The term 'pinguecula' refers to a pyramid-like growth that appears as a yellow discoloration on the conjunctiva. It is a deposit of protein, fat, or calcium that is found close to the edge of the cornea. In fact, the word 'pinguecula' comes from a Latin word that originally means 'fatty'.

Pinguecula is thought to be caused by a combination of dry eyes and exposure to wind, dust, or ultraviolet light from the sun.

The best methods to prevent a pinguecula is protect the eye from ultraviolet radiation by wearing sunglasses and brimmed hats while outdoors.

Diabetic retinopathy is a complication of diabetes, and causes damage to the blood vessels in the retina.

Many diabetics – particularly those with poor diabetic control which results in too-high blood sugar levels over long periods of time – have damaged blood vessels in the retina, the tissue lining the back of the eye that detects light and allows us to see. This condition, called diabetic retinopathy, affects up to eight out of 10 patients who have had diabetes for 10 years or more.

Diabetic retinopathy typically presents no symptoms during the early stages.

• Sudden or complete loss of vision
• Blurred vision
• Impairment of color vision
• Floaters, or transparent and colorless spots and dark strings that float in the patient's field of vision
• Patches or streaks that block the person's vision
• Poor night vision

Regular eye checks are essential for all diabetics, so signs of diabetic retinopathy can be detected as early as possible

Floaters are shapes or shadows that people can see drifting across their vision. The exact form and source of these floaters vary – they may appear as small dots or irregularly shaped strands. Floaters are generally harmless and can become less noticeable over time, however in some cases they can be an indication of serious eye conditions especially when they are associated with flashes of light

The hollow space in the middle of your eyeball is filled by a clear, jelly-like substance called the vitreous humor. As we get older, small pockets of fluid form within the gel. Eventually, some of this fluid moves in between the gel and the retina, causing the vitreous to peel away from the retina. The retina, which is like the film of a camera, is then able to see the outer part of this gel floating inside the eye – and this is what causes floaters.

Age-Related Macular Degeneration, also known as AMD or ARMD is a common eye condition and one of the leading causes of loss of vision among people age 50 and older in the developed world.

The small spot on the back of your eye (Retina) is called the macula and is made of millions of light sensing cells that provide you with sharp central vision. AMD causes damage to this area and can lead to a blurred spot in your central vision which can interfere in simple tasks like face identification, driving, reading and writing and leads to a much lower quality of life.

In very few cases will the vision loss be sudden. AMD usually produces a slow painless loss of vision. Early signs of Macular Degeneration will include shadows in your central vision or unusual fuzziness or distorted vision.

Many eye care providers are concerned that the added blue light exposure from computer screens, smartphones and other digital devices might increase a person's risk of AMD later in life. The situation gets worsened as infants and children are increasingly being exposed to digital devices like mobile phones, tablets etc. on a regular basis.

Retinal detachment occurs when the delicate layer of nerves at the back of your eye (the retina) begins to pull away from the blood vessels that supply it with oxygen.since the retina can't work properly when this happens, you could have permanent vision loss if you don’t get it treated right away.

Symptoms

• Flashes of Light
• Floaters of threads in front of the eye
• Loss of peripheral vision

without early treatment, retinal detachment could lead to permanent vision loss in the affected eye. So if you experience any of these symptoms, it’s important that you see an eye care professional as soon as possible.

Dry eyes occur when the eyes either don’t make enough tears, or the quality of the tears produced is reduced, which means the tears can evaporate rapidly from the surface of the eye, allowing the eye to dry. Often, the reduced tear quality is a result of blockage or inflammation of the oil glands within the lid margin. When the surface of the eyes dry out, the eyes become inflamed. They appear red, and the whites of the eyes can appear to be pink and swollen. Normally, the eyes become very irritable

Symptoms include Foreign body sensation/feels like something is in the eyes,Eyes feel ‘gritty’ – often worse in the mornings,Blurred vision,Burning sensation in eyes,Irritable eyelids,Light sensitivityRedness of the whites of the eyes,Painful eyes,Excessive watering

Dry eye has a number of causes. It happens mostly as a part of the natural ageing process but can also be caused by problems with blinking or problems with the glands.commmonly found in Ageing over 60’s are the commonest group to suffer,Hot, dry or windy climates – causes evaporation of tears,Inflammatory diseases – e.g. Rheumatoid arthritis affecting joints, is associated with higher risk of dry eyes.,Side effects from medications – e.g. The oral contraceptive pill etc.

A subconjunctival hemorrhage is a bleed underneath the conjunctiva- the transparent layer which lies over the white of the eye (the sclera). This bleeding is caused by the leaking of a blood vessel in the conjunctiva.

It is usually painless and does not affect eyesight, though it can sometimes cause an ache or discomfort in the eye. Sometimes, it might go unnoticed until somebody draws attention to it.

Subconjunctival hemorrhages are very common because the blood vessels in the conjunctiva are very fragile and can easily bleed a little. In most cases, there is no specific cause but the following are associated with the condition:

• Rigorus activities
• Coughing and sneezing,Vomiting
• High blood pressure and taking blood-thinning medications such as aspirin
• A subconjunctival hemorrhage can also happen following an eye operation.
• Other potential causes include injury to the eye or rubbing the eye forcefully.