The patient will complain of decreased visual acuity. This is the most common complaint and only when the visual acuity is affected significantly is a cataract considered clinically relevant. Another frequent complaint is increased glare from oncoming headlights at night and brightly lit environment during the day. Patient with cataract may also experience varying degrees of myopia due to the increase in diopteric power of the lens, patient will report an improvement in their near vision and a decreased need for their reading glasses. This improved vision is unfortunately temporary and will disappear as the cataract worsens.
The cataract is also staged at presentation with the use of a visual acuity chart. A patient who cannot see better than 20/200 is said to have a mature cataract[6].

• Collapse

  “We can’t continue to provide ever-more-expensive treatments to an ever-increasing group of patients and not expect the system to collapse.” [theguardian.com]

  […] incision decentration Incomplete or interrupted capsulotomy, fragmentation, or corneal incision procedure Capsular tear Corneal abrasion or defect Pain Infection Bleeding Damage to intraocular structures Anterior chamber fluid leakage, anterior chamber collapse [lensxlasers.com]

  […] intraocular lens (IOL) insertion followed by pars plana vitrectomy; PPPV), a smaller corneal wound size may have additional advantages to the subsequent vitrectomy, including avoiding the need for wound suturing and preventing the anterior chamber from collapsing [doi.org]

  Fluid removed is continually replaced with a saline solution to prevent collapse of the structure of the anterior chamber (the front part of the eye). [en.wikipedia.org]

• Asymptomatic

  Health care professionals often recommend that all people should have periodic and thorough eye examinations as part of routine primary care, especially since many eye diseases are asymptomatic. [en.wikipedia.org]

• Fatigue

  Christodoulou Fatigue in multiple sclerosis Curr Neurol Neurosci Rep, 1 (2001), pp. 294–298 ^ a b c "Preventing Slips, Trips, and Falls in Wholesale and Retail Trade Establishments" (Press release). [en.wikipedia.org]

• Jaundice

  They include difficulty feeding, diarrhea, lethargy, hypotonia, jaundice, cataract, and hepatomegaly (enlarged liver). [en.wikipedia.org]

• Visual Impairment

  Cataracts remain one of the leading causes of visual impairment globally; they are responsible for blindness in 20 million people worldwide. Cataracts are one of the leading causes of visual impairment globally. [theconversation.com]

  The new WHO Action Plan mandates that national governments collect data on cataract indicators of blindness and visual impairment. [iapb.org]

  The clouding causes distortion of light, as it passes through the lens, resulting in visual impairment and glare. Initially, a cataract presents discretely and may even go unnoticed, but the visual impairment worsens as the cataract grows larger. [amboss.com]

  They can affect one or both eyes and can produce severe visual impairment and amblyopia. [britannica.com]

  Moderate visual impairment combined with severe visual impairment are grouped under the term “low vision” : low vision taken together with blindness represents all visual impairment. [web.archive.org]

• Blurred Vision

  Besides blurred vision, the symptoms include glare and difficulty driving at night. [nytimes.com]

  Vision changes, such as blurred vision and discomfort with bright light, may occur for a short time after surgery. [msdmanuals.com]

  Common symptoms include: Deterioration of your distance and reading vision Hazy, fuzzy, blurred or double vision Increased sensitivity to light and glare Difficulty driving at night Little improvement in vision, even with stronger glasses Causes of cataracts [eyeinstitute.co.nz]

  This is generally when cataract surgery is considered, though sometimes cataract surgery is done for reasons other than vision. What are the symptoms? Cloudy or blurred vision. [eyenm.com]

  What causes blurred vision? Just as fingerprints on a camera lens cause blurred pictures regardless of our efforts to focus, a cloudy lens within the eye causes blurred vision. [changcataract.com]

• Visual Impairment

  Cataracts remain one of the leading causes of visual impairment globally; they are responsible for blindness in 20 million people worldwide. Cataracts are one of the leading causes of visual impairment globally. [theconversation.com]

  The new WHO Action Plan mandates that national governments collect data on cataract indicators of blindness and visual impairment. [iapb.org]

  The clouding causes distortion of light, as it passes through the lens, resulting in visual impairment and glare. Initially, a cataract presents discretely and may even go unnoticed, but the visual impairment worsens as the cataract grows larger. [amboss.com]

  They can affect one or both eyes and can produce severe visual impairment and amblyopia. [britannica.com]

  Moderate visual impairment combined with severe visual impairment are grouped under the term “low vision” : low vision taken together with blindness represents all visual impairment. [web.archive.org]

• Diplopia

  Cataract Symptom: Double Vision Diplopia, or double vision, when looking with one eye can be another symptom of cataracts. This is not the same as diplopia that arises from improper alignment of the eyes. [onhealth.com]

  Second sight Opacities within the red reflex, darkening of the red reflex, or obscuration of ocular fundus detail during opthalmoscopy Grey, white, yellow, or brownish clouding of the lens Monocular diplopia Hyperopia (in cortical cataract) Change in [amboss.com]

  Once symptoms of cataracts develop, they may include: cloudy or blurry vision; double vision (diplopia) ; a sense that colors appear faded; seeing halos around lights; an increased sensitivity to glare; and a distortion of vision that makes objects appear [hopkinsmedicine.org]

  Frequency: 1 Quality: Maltese lenti mċajpra fl-għajn (katarretta) English cloudy lens in the eye (cataract) Last Update: 2017-04-26 Usage Frequency: 1 Quality: Maltese Vista mċajpra Diplopja Katarretta Konġuntivite Għajn xotta English Vision blurred Diplopia [mymemory.translated.net]

  Distance vision: Tumbling E chart, Landolt C chart Eye teaming (binocularity) Eye movement Accommodation (focusing skills) Peripheral vision Eye–hand coordination Conditions diagnosed during eye examinations[edit] Myopia Hyperopia Presbyopia Amblyopia Diplopia [en.wikipedia.org]

• Photophobia

  Photophobia, increased light sensitivity is perhaps the most common symptom of small opacities that do not yet reduce visual acuity notably. Then it is important to use a hat or a visor so the light does not fall directly on the eyes. [lea-test.fi]

  Early symptoms may be loss of contrast, glare (ie, halos and starbursts around lights, not photophobia), needing more light to see well, and problems distinguishing dark blue from black. Painless blurring eventually occurs. [merckmanuals.com]

  Some children will be given eye patches or shields to help prevent itching, injury, and photophobia (sensitivity to light). Your eye doctor will recommend a wear schedule for your child. [eyehealthweb.com]

• Stupor

  Accordingly, the plural of the Greek word for ‘drowsiness, stupor’ was used to give a name of those arteries. [web.archive.org]

A thorough history and physical examination is enough to make a diagnosis a cataracts. However, laboratory investigations may be required to screen for underlying diseases like blood sugar for diabetes mellitus. Also, laboratory tests are an essential part of pre-surgical work up so the baseline investigations should be carried out and clotting factors to prevent perioperative bleeding.
Imaging studies are ordered when a dense cataract obscures the view of the posterior part of the eye when a posterior pole pathology is suspected.
There are special tests that could also be requested there is suspicion of coexisting ocular disease e.g a Maddox rod test in a patient with suspected macular problems[7].

The treatment for cataract is surgical and there has been no proven medical remedy till date and the definitive surgical remedy is lens extraction and replacement with an intraocular lens and there are various techniques for this procedure.
The intracapsular cataract extraction or ICCE involves the extraction of the entire lens and posterior capsule. This procedure is contraindicated in children and young adults.
Extracapsular cataract extraction or ECCE involves the removal of the lens through an opening in the anterior capsule and preserving the posterior capsule. This procedure has a number of advantages over ICCE[8].
Phacoemulsification is a more modern technique. It involves the use of an ultrasonically driven needle to break the lens down to tinier bits and aspirate these bits through a needle port. It offers some advantages over the ECCE like smaller incisions and faster wound healing.

The prognosis following surgery is very favorable if there are no accompanying ocular diseases prior to surgery that could affect vision. Cystoid macular edema is the main cause of morbidity following cataract surgery. In patients with diabetes and diabetic retinopathy, the visual prognosis is not very good[6].

The precise cause of the changes that occur in the lens with age is not known, however many factors have been implicated as contributory including chronic illnesses like diabetes and hypertension, ultraviolet light, smoking, previous eye injury, positive family history, prolonged corticosteroid use, previous eye surgery, alcoholism, hormone replacement therapy and use of statins (cholesterol lowering drugs).
Congenital cataracts could be caused by intrauterine infections like rubella, syphillis and cytomegalovirus, genetically transmitted syndromes and metabolic disorders[2].

Cataract is the leading cause of blindness worldwide and is responsible for as much as 51% of the world's blindness. As at 2004, it was estimated that about 53.8million of the world’s population experience some form of disability due to cataract. Of that number, 52.2million are in developing and underdeveloped countries. This is probably due to the inadequacy of surgical services in those countries or barriers in assessing these services. The incidence of senile cataract increases with advancing age and as much as 67% in patients aged 70 and over. The costs of treating cataract yearly is estimated at 6.8 billion dollars making it a public health concern[3].
Cataract affects more women than men and there is no documented evidence to show racial predilection.

The pathophysiology of cataract cuts across many factors and involves intricate interactions between various physiological processes. The weight and thickness of the lens increases as it ages while the accommodative power decreases, a process called nuclear sclerosis then occurs. It is when the central nucleus of the lens becomes compressed and hardened due to the addition of cortical layers in a concentric pattern. Another mechanism is the decrease in epithelial cell density due to the accumulation of small scale epithelial losses which eventually leads to loss of lens transparency. Also, there could be progressive oxidative damage to the lens. Another mechanism is the when soluble low molecular weight cytoplasmic lens proteins are converted to soluble high molecular weight aggregates[4].

Some preventive steps include wearing sunglasses to block UV lights, preventing risk factors like diabetes and hypercholesterolemia, and use of dietary supplement like vitamins E and C. There is however no literature to back this up[9].

Cataract is usually a visible opacity in the lens. When it located on the visual axis, it will lead to visual loss. Although there are other types of cataracts like secondary, traumatic, congenital and radiation cataracts, the commonest type is the one related to aging also known as senile cataracts. Visual loss in cataract is gradual and it can affect either or both eyes. It cannot be transmitted from one eye to the other[1].

• Definition: cataract is the clouding or progressive thickening of the lens in the eye. It is mostly a disease of old age although it can be seen in younger adult following trauma and also, some babies are born with it. 
• Cause: some of the factors that could lead to development of cataract are diabetes, hypertension, drugs like oral contraceptive and cholesterol lowering drugs, UV radiation from the sun, smoking, chronic alcoholism, and hormone replacement therapy.
• Symptoms: The main symptom is poor vision, you could also experience glare when in a brightly lit room or from headlamps in oncoming vehicles. You could also experience improved near vision but this is usually short-lived[10].
• Diagnosis: Diagnosis is often made on the basis of the history and physical examination. Some laboratory tests may however be required to check for underlying diseases and to check the normal functioning of the body prior to surgery.
• Treatment. The main treatment of cataract is surgical. Surgery involves removal of the lens through one of many procedures and implantation of a plastic device known as intraocular lens.

1. Kuszak JR, Deutsch TA, Brown HG. Anatomy of aged and senile cataractous lens. In: Principles and Practice of Ophthalmology, Albert DM, Jakobiec FA. (Eds), WB Saunders Company, Philadelphia 1994. p.564.
2. Congdon N, O'Colmain B, Klaver CC. Causes and prevalence of visual impairment among adults in the United States. Arch Ophthalmol 2004; 122:477.
3. Schaumberg DA, Mendes F, Balaram M. Accumulated lead exposure and risk of age-related cataract in men. JAMA 2004; 292:2750.
4. Clark A, Morlet N, Ng JQ. Whole population trends in complications of cataract surgery over 22 years in Western Australia. Ophthalmology 2011; 118:1055.
5. Hamed WW, Fedorowicz Z. Day care versus in-patient surgery for age-related cataract. Cochrane Database Syst Rev 2004; :CD004242.
6. Kessel L, Tendal B, Jørgensen KJ. Post-cataract prevention of inflammation and macular edema by steroid and nonsteroidal anti-inflammatory eye drops: a systematic review. Ophthalmology 2014; 121:1915.
7. Kessel L, Tendal B, Jørgensen KJ. Post-cataract prevention of inflammation and macular edema by steroid and nonsteroidal anti-inflammatory eye drops: a systematic review. Ophthalmology 2014; 121:1915.
8. Agarwal A, Kumar DA. Cost-effectiveness of cataract surgery. Curr Opin Ophthalmol 2011; 22:15.
9. Shingleton BJ, Hersh PS, Kenyon KR. Lens injuries. In: Eye Trauma. 1991:126-34.
10. Kanski JJ. Clinical Ophthalmology: A Systematic Approach. 1989:257-8.